xref: /external/mockito/src/org/mockito/Mockito.java

/*
 * Copyright (c) 2007 Mockito contributors
 * This program is made available under the terms of the MIT License.
 */
package org.mockito;

import org.mockito.internal.MockitoCore;
import org.mockito.internal.creation.MockSettingsImpl;
import org.mockito.internal.debugging.MockitoDebuggerImpl;
import org.mockito.internal.stubbing.answers.*;
import org.mockito.internal.stubbing.defaultanswers.ReturnsEmptyValues;
import org.mockito.internal.stubbing.defaultanswers.ReturnsMoreEmptyValues;
import org.mockito.internal.verification.VerificationModeFactory;
import org.mockito.runners.MockitoJUnitRunner;
import org.mockito.stubbing.*;
import org.mockito.verification.Timeout;
import org.mockito.verification.VerificationMode;
import org.mockito.verification.VerificationWithTimeout;

/**
 * <p align="left"><img src="logo.jpg"/></p>
 * Mockito library enables mocks creation, verification and stubbing.
 * <p>
 * This javadoc content is also available on the <a href="http://mockito.org">http://mockito.org</a> web page.
 * All documentation is kept in javadocs because it guarantees consistency between what's on the web and what's in the source code.
 * Also, it makes possible to access documentation straight from the IDE even if you work offline.
 *
 * <h1>Contents</h1>
 *
 * <b>
 *      <a href="#1">1. Let's verify some behaviour! </a><br/>
 *      <a href="#2">2. How about some stubbing? </a><br/>
 *      <a href="#3">3. Argument matchers </a><br/>
 *      <a href="#4">4. Verifying exact number of invocations / at least once / never </a><br/>
 *      <a href="#5">5. Stubbing void methods with exceptions </a><br/>
 *      <a href="#6">6. Verification in order </a><br/>
 *      <a href="#7">7. Making sure interaction(s) never happened on mock </a><br/>
 *      <a href="#8">8. Finding redundant invocations </a><br/>
 *      <a href="#9">9. Shorthand for mocks creation - <code>&#064;Mock</code> annotation </a><br/>
 *      <a href="#10">10. Stubbing consecutive calls (iterator-style stubbing) </a><br/>
 *      <a href="#11">11. Stubbing with callbacks </a><br/>
 *      <a href="#12">12. <code>doReturn()</code>|<code>doThrow()</code>|<code>doAnswer()</code>|<code>doNothing()</code>|<code>doCallRealMethod()</code> family of methods</a><br/>
 *      <a href="#13">13. Spying on real objects </a><br/>
 *      <a href="#14">14. Changing default return values of unstubbed invocations (Since 1.7) </a><br/>
 *      <a href="#15">15. Capturing arguments for further assertions (Since 1.8.0) </a><br/>
 *      <a href="#16">16. Real partial mocks (Since 1.8.0) </a><br/>
 *      <a href="#17">17. Resetting mocks (Since 1.8.0) </a><br/>
 *      <a href="#18">18. Troubleshooting & validating framework usage (Since 1.8.0) </a><br/>
 *      <a href="#19">19. Aliases for behavior driven development (Since 1.8.0) </a><br/>
 *      <a href="#20">20. Serializable mocks (Since 1.8.1) </a><br/>
 *      <a href="#21">21. New annotations: <code>&#064;Captor</code>, <code>&#064;Spy</code>, <code>&#064;InjectMocks</code> (Since 1.8.3) </a><br/>
 *      <a href="#22">22. Verification with timeout (Since 1.8.5) </a><br/>
 *      <a href="#23">23. (New) Automatic instantiation of <code>&#064;Spies</code>, <code>&#064;InjectMocks</code> and constructor injection goodness (Since 1.9.0)</a><br/>
 *      <a href="#24">24. (New) One-liner stubs (Since 1.9.0)</a><br/>
 *      <a href="#25">25. (New) Verification ignoring stubs (Since 1.9.0)</a><br/>
 *      <a href="#26">26. (**New**) Mocking details (Since 1.9.5)</a><br/>
 *      <a href="#27">27. (**New**) Delegate calls to real instance (Since 1.9.5)</a><br/>
 *      <a href="#28">28. (**New**) <code>MockMaker</code> API (Since 1.9.5)</a><br/>
 * </b>
 *
 * <p>
 * Following examples mock a List, because everyone knows its interface (methods
 * like <code>add()</code>, <code>get()</code>, <code>clear()</code> will be used). <br>
 * You probably wouldn't mock List class 'in real'.
 *
 *
 *
 *
 * <h3 id="1">1. <a class="meaningful_link" href="#verification">Let's verify some behaviour!</a></h3>
 *
 * <pre class="code"><code class="java">
 * //Let's import Mockito statically so that the code looks clearer
 * import static org.mockito.Mockito.*;
 *
 * //mock creation
 * List mockedList = mock(List.class);
 *
 * //using mock object
 * mockedList.add("one");
 * mockedList.clear();
 *
 * //verification
 * verify(mockedList).add("one");
 * verify(mockedList).clear();
 * </code></pre>
 *
 * <p>
 * Once created, mock will remember all interactions. Then you can selectively
 * verify whatever interaction you are interested in.
 *
 *
 *
 *
 * <h3 id="2">2. <a class="meaningful_link" href="#stubbing">How about some stubbing?</a></h3>
 *
 * <pre class="code"><code class="java">
 * //You can mock concrete classes, not only interfaces
 * LinkedList mockedList = mock(LinkedList.class);
 *
 * //stubbing
 * when(mockedList.get(0)).thenReturn("first");
 * when(mockedList.get(1)).thenThrow(new RuntimeException());
 *
 * //following prints "first"
 * System.out.println(mockedList.get(0));
 *
 * //following throws runtime exception
 * System.out.println(mockedList.get(1));
 *
 * //following prints "null" because get(999) was not stubbed
 * System.out.println(mockedList.get(999));
 *
 * //Although it is possible to verify a stubbed invocation, usually <b>it's just redundant</b>
 * //If your code cares what get(0) returns then something else breaks (often before even verify() gets executed).
 * //If your code doesn't care what get(0) returns then it should not be stubbed. Not convinced? See <a href="http://monkeyisland.pl/2008/04/26/asking-and-telling">here</a>.
 * verify(mockedList).get(0);
 * </code></pre>
 *
 * <ul>
 * <li> By default, for all methods that return value, mock returns null, an
 * empty collection or appropriate primitive/primitive wrapper value (e.g: 0,
 * false, ... for int/Integer, boolean/Boolean, ...). </li>
 *
 * <li> Stubbing can be overridden: for example common stubbing can go to
 * fixture setup but the test methods can override it.
 * Please note that overridding stubbing is a potential code smell that points out too much stubbing</li>
 *
 * <li> Once stubbed, the method will always return stubbed value regardless
 * of how many times it is called. </li>
 *
 * <li> Last stubbing is more important - when you stubbed the same method with
 * the same arguments many times.
 * Other words: <b>the order of stubbing matters</b> but it is only meaningful rarely,
 * e.g. when stubbing exactly the same method calls or sometimes when argument matchers are used, etc.</li>
 *
 * </ul>
 *
 *
 *
 * <h3 id="3">3. <a class="meaningful_link" href="#argument_matchers">Argument matchers</a></h3>
 *
 * Mockito verifies argument values in natural java style: by using an <code>equals()</code> method.
 * Sometimes, when extra flexibility is required then you might use argument matchers:
 *
 * <pre class="code"><code class="java">
 * //stubbing using built-in anyInt() argument matcher
 * when(mockedList.get(anyInt())).thenReturn("element");
 *
 * //stubbing using hamcrest (let's say isValid() returns your own hamcrest matcher):
 * when(mockedList.contains(argThat(isValid()))).thenReturn("element");
 *
 * //following prints "element"
 * System.out.println(mockedList.get(999));
 *
 * //<b>you can also verify using an argument matcher</b>
 * verify(mockedList).get(anyInt());
 * </code></pre>
 *
 * <p>
 * Argument matchers allow flexible verification or stubbing.
 * {@link Matchers Click here to see} more built-in matchers
 * and examples of <b>custom argument matchers / hamcrest matchers</b>.
 * <p>
 * For information solely on <b>custom argument matchers</b> check out javadoc for {@link ArgumentMatcher} class.
 * <p>
 * Be reasonable with using complicated argument matching.
 * The natural matching style using <code>equals()</code> with occasional <code>anyX()</code> matchers tend to give clean & simple tests.
 * Sometimes it's just better to refactor the code to allow <code>equals()</code> matching or even implement <code>equals()</code> method to help out with testing.
 * <p>
 * Also, read <a href="#15">section 15</a> or javadoc for {@link ArgumentCaptor} class.
 * {@link ArgumentCaptor} is a special implementation of an argument matcher that captures argument values for further assertions.
 * <p>
 * <b>Warning on argument matchers:</b>
 * <p>
 * If you are using argument matchers, <b>all arguments</b> have to be provided
 * by matchers.
 * <p>
 * E.g: (example shows verification but the same applies to stubbing):
 *
 * <pre class="code"><code class="java">
 *   verify(mock).someMethod(anyInt(), anyString(), <b>eq("third argument")</b>);
 *   //above is correct - eq() is also an argument matcher
 *
 *   verify(mock).someMethod(anyInt(), anyString(), <b>"third argument"</b>);
 *   //above is incorrect - exception will be thrown because third argument is given without an argument matcher.
 * </code></pre>
 *
 * <p>
 * Matcher methods like <code>anyObject()</code>, <code>eq()</code> <b>do not</b> return matchers.
 * Internally, they record a matcher on a stack and return a dummy value (usually null).
 * This implementation is due static type safety imposed by java compiler.
 * The consequence is that you cannot use <code>anyObject()</code>, <code>eq()</code> methods outside of verified/stubbed method.
 *
 *
 *
 *
 * <h3 id="4">4. <a class="meaningful_link" href="#exact_verification">Verifying exact number of invocations</a> /
 * <a class="meaningful_link" href="#at_least_verification">at least x</a> / never</h3>
 *
 * <pre class="code"><code class="java">
 * //using mock
 * mockedList.add("once");
 *
 * mockedList.add("twice");
 * mockedList.add("twice");
 *
 * mockedList.add("three times");
 * mockedList.add("three times");
 * mockedList.add("three times");
 *
 * //following two verifications work exactly the same - times(1) is used by default
 * verify(mockedList).add("once");
 * verify(mockedList, times(1)).add("once");
 *
 * //exact number of invocations verification
 * verify(mockedList, times(2)).add("twice");
 * verify(mockedList, times(3)).add("three times");
 *
 * //verification using never(). never() is an alias to times(0)
 * verify(mockedList, never()).add("never happened");
 *
 * //verification using atLeast()/atMost()
 * verify(mockedList, atLeastOnce()).add("three times");
 * verify(mockedList, atLeast(2)).add("five times");
 * verify(mockedList, atMost(5)).add("three times");
 *
 * </code></pre>
 *
 * <p>
 * <b>times(1) is the default.</b> Therefore using times(1) explicitly can be
 * omitted.
 *
 *
 *
 *
 * <h3 id="5">5. <a class="meaningful_link" href="#stubbing_with_exceptions">Stubbing void methods with exceptions</a></h3>
 *
 * <pre class="code"><code class="java">
 *   doThrow(new RuntimeException()).when(mockedList).clear();
 *
 *   //following throws RuntimeException:
 *   mockedList.clear();
 * </code></pre>
 *
 * Read more about doThrow|doAnswer family of methods in paragraph 12.
 * <p>
 * Initially, {@link Mockito#stubVoid(Object)} was used for stubbing voids.
 * Currently <code>stubVoid()</code> is deprecated in favor of {@link Mockito#doThrow(Throwable)}.
 * This is because of improved readability and consistency with the family of {@link Mockito#doAnswer(Answer)} methods.
 *
 *
 *
 *
 * <h3 id="6">6. <a class="meaningful_link" href="#in_order_verification">Verification in order</a></h3>
 *
 * <pre class="code"><code class="java">
 * // A. Single mock whose methods must be invoked in a particular order
 * List singleMock = mock(List.class);
 *
 * //using a single mock
 * singleMock.add("was added first");
 * singleMock.add("was added second");
 *
 * //create an inOrder verifier for a single mock
 * InOrder inOrder = inOrder(singleMock);
 *
 * //following will make sure that add is first called with "was added first, then with "was added second"
 * inOrder.verify(singleMock).add("was added first");
 * inOrder.verify(singleMock).add("was added second");
 *
 * // B. Multiple mocks that must be used in a particular order
 * List firstMock = mock(List.class);
 * List secondMock = mock(List.class);
 *
 * //using mocks
 * firstMock.add("was called first");
 * secondMock.add("was called second");
 *
 * //create inOrder object passing any mocks that need to be verified in order
 * InOrder inOrder = inOrder(firstMock, secondMock);
 *
 * //following will make sure that firstMock was called before secondMock
 * inOrder.verify(firstMock).add("was called first");
 * inOrder.verify(secondMock).add("was called second");
 *
 * // Oh, and A + B can be mixed together at will
 * </code></pre>
 *
 * Verification in order is flexible - <b>you don't have to verify all
 * interactions</b> one-by-one but only those that you are interested in
 * testing in order.
 * <p>
 * Also, you can create InOrder object passing only mocks that are relevant for
 * in-order verification.
 *
 *
 *
 *
 * <h3 id="7">7. <a class="meaningful_link" href="#never_verification">Making sure interaction(s) never happened on mock</a></h3>
 *
 * <pre class="code"><code class="java">
 * //using mocks - only mockOne is interacted
 * mockOne.add("one");
 *
 * //ordinary verification
 * verify(mockOne).add("one");
 *
 * //verify that method was never called on a mock
 * verify(mockOne, never()).add("two");
 *
 * //verify that other mocks were not interacted
 * verifyZeroInteractions(mockTwo, mockThree);
 *
 * </code></pre>
 *
 *
 *
 *
 * <h3 id="8">8. <a class="meaningful_link" href="#finding_redundant_invocations">Finding redundant invocations</a></h3>
 *
 * <pre class="code"><code class="java">
 * //using mocks
 * mockedList.add("one");
 * mockedList.add("two");
 *
 * verify(mockedList).add("one");
 *
 * //following verification will fail
 * verifyNoMoreInteractions(mockedList);
 * </code></pre>
 *
 * A word of <b>warning</b>:
 * Some users who did a lot of classic, expect-run-verify mocking tend to use <code>verifyNoMoreInteractions()</code> very often, even in every test method.
 * <code>verifyNoMoreInteractions()</code> is not recommended to use in every test method.
 * <code>verifyNoMoreInteractions()</code> is a handy assertion from the interaction testing toolkit. Use it only when it's relevant.
 * Abusing it leads to <strong>overspecified</strong>, <strong>less maintainable</strong> tests. You can find further reading
 * <a href="http://monkeyisland.pl/2008/07/12/should-i-worry-about-the-unexpected/">here</a>.
 *
 * <p>
 * See also {@link Mockito#never()} - it is more explicit and
 * communicates the intent well.
 * <p>
 *
 *
 *
 *
 * <h3 id="9">9. <a class="meaningful_link" href="#mock_annotation">Shorthand for mocks creation - <code>&#064;Mock</code> annotation</a></h3>
 *
 * <ul>
 * <li>Minimizes repetitive mock creation code.</li>
 * <li>Makes the test class more readable.</li>
 * <li>Makes the verification error easier to read because the <b>field name</b>
 * is used to identify the mock.</li>
 * </ul>
 *
 * <pre class="code"><code class="java">
 *   public class ArticleManagerTest {
 *
 *       &#064;Mock private ArticleCalculator calculator;
 *       &#064;Mock private ArticleDatabase database;
 *       &#064;Mock private UserProvider userProvider;
 *
 *       private ArticleManager manager;
 * </code></pre>
 *
 * <b>Important!</b> This needs to be somewhere in the base class or a test
 * runner:
 *
 * <pre class="code"><code class="java">
 * MockitoAnnotations.initMocks(testClass);
 * </code></pre>
 *
 * You can use built-in runner: {@link MockitoJUnitRunner}.
 * <p>
 * Read more here: {@link MockitoAnnotations}
 *
 *
 *
 *
 * <h3 id="10">10. <a class="meaningful_link" href="#stubbing_consecutive_calls">Stubbing consecutive calls</a> (iterator-style stubbing)</h3>
 *
 * Sometimes we need to stub with different return value/exception for the same
 * method call. Typical use case could be mocking iterators.
 * Original version of Mockito did not have this feature to promote simple mocking.
 * For example, instead of iterators one could use {@link Iterable} or simply
 * collections. Those offer natural ways of stubbing (e.g. using real
 * collections). In rare scenarios stubbing consecutive calls could be useful,
 * though:
 * <p>
 *
 * <pre class="code"><code class="java">
 * when(mock.someMethod("some arg"))
 *   .thenThrow(new RuntimeException())
 *   .thenReturn("foo");
 *
 * //First call: throws runtime exception:
 * mock.someMethod("some arg");
 *
 * //Second call: prints "foo"
 * System.out.println(mock.someMethod("some arg"));
 *
 * //Any consecutive call: prints "foo" as well (last stubbing wins).
 * System.out.println(mock.someMethod("some arg"));
 * </code></pre>
 *
 * Alternative, shorter version of consecutive stubbing:
 *
 * <pre class="code"><code class="java">
 * when(mock.someMethod("some arg"))
 *   .thenReturn("one", "two", "three");
 * </code></pre>
 *
 *
 *
 *
 * <h3 id="11">11. <a class="meaningful_link" href="#answer_stubs">Stubbing with callbacks</a></h3>
 *
 * Allows stubbing with generic {@link Answer} interface.
 * <p>
 * Yet another controversial feature which was not included in Mockito
 * originally. We recommend using simple stubbing with <code>thenReturn()</code> or
 * <code>thenThrow()</code> only. Those two should be <b>just enough</b> to test/test-drive
 * any clean & simple code.
 *
 * <pre class="code"><code class="java">
 * when(mock.someMethod(anyString())).thenAnswer(new Answer() {
 *     Object answer(InvocationOnMock invocation) {
 *         Object[] args = invocation.getArguments();
 *         Object mock = invocation.getMock();
 *         return "called with arguments: " + args;
 *     }
 * });
 *
 * //Following prints "called with arguments: foo"
 * System.out.println(mock.someMethod("foo"));
 * </code></pre>
 *
 *
 *
 *
 * <h3 id="12">12. <a class="meaningful_link" href="#do_family_methods_stubs"><code>doReturn()</code>|<code>doThrow()</code>|
 * <code>doAnswer()</code>|<code>doNothing()</code>|<code>doCallRealMethod()</code> family of methods</a></h3>
 *
 * Stubbing voids requires different approach from {@link Mockito#when(Object)} because the compiler does not
 * like void methods inside brackets...
 * <p>
 * {@link Mockito#doThrow(Throwable)} replaces the {@link Mockito#stubVoid(Object)} method for stubbing voids.
 * The main reason is improved readability and consistency with the family of <code>doAnswer()</code> methods.
 * <p>
 * Use <code>doThrow()</code> when you want to stub a void method with an exception:
 * <pre class="code"><code class="java">
 *   doThrow(new RuntimeException()).when(mockedList).clear();
 *
 *   //following throws RuntimeException:
 *   mockedList.clear();
 * </code></pre>
 *
 * <p>
 * You can use <code>doThrow()</code>, <code>doAnswer()</code>, <code>doNothing()</code>, <code>doReturn()</code>
 * and <code>doCallRealMethod()</code> in place of the corresponding call with <code>when()</code>, for any method.
 * It is necessary when you
 * <ul>
 *     <li>stub void methods</li>
 *     <li>stub methods on spy objects (see below)</li>
 *     <li>stub the same method more than once, to change the behaviour of a mock in the middle of a test.</li>
 * </ul>
 * but you may prefer to use these methods in place of the alternative with <code>when()</code>, for all of your stubbing calls.
 * <p>
 * Read more about these methods:
 * <p>
 * {@link Mockito#doReturn(Object)}
 * <p>
 * {@link Mockito#doThrow(Throwable)}
 * <p>
 * {@link Mockito#doThrow(Class)}
 * <p>
 * {@link Mockito#doAnswer(Answer)}
 * <p>
 * {@link Mockito#doNothing()}
 * <p>
 * {@link Mockito#doCallRealMethod()}
 *
 *
 *
 *
 * <h3 id="13">13. <a class="meaningful_link" href="#spy">Spying on real objects</a></h3>
 *
 * You can create spies of real objects. When you use the spy then the <b>real</b> methods are called
 * (unless a method was stubbed).
 * <p>
 * Real spies should be used <b>carefully and occasionally</b>, for example when dealing with legacy code.
 *
 * <p>
 * Spying on real objects can be associated with "partial mocking" concept.
 * <b>Before the release 1.8</b>, Mockito spies were not real partial mocks.
 * The reason was we thought partial mock is a code smell.
 * At some point we found legitimate use cases for partial mocks
 * (3rd party interfaces, interim refactoring of legacy code, the full article is <a href=
 * "http://monkeyisland.pl/2009/01/13/subclass-and-override-vs-partial-mocking-vs-refactoring"
 * >here</a>)
 * <p>
 *
 * <pre class="code"><code class="java">
 *   List list = new LinkedList();
 *   List spy = spy(list);
 *
 *   //optionally, you can stub out some methods:
 *   when(spy.size()).thenReturn(100);
 *
 *   //using the spy calls <b>*real*</b> methods
 *   spy.add("one");
 *   spy.add("two");
 *
 *   //prints "one" - the first element of a list
 *   System.out.println(spy.get(0));
 *
 *   //size() method was stubbed - 100 is printed
 *   System.out.println(spy.size());
 *
 *   //optionally, you can verify
 *   verify(spy).add("one");
 *   verify(spy).add("two");
 * </code></pre>
 *
 * <h4>Important gotcha on spying real objects!</h4>
 * <ol>
 * <li>Sometimes it's impossible or impractical to use {@link Mockito#when(Object)} for stubbing spies.
 * Therefore when using spies please consider <code>doReturn</code>|<code>Answer</code>|<code>Throw()</code> family of
 * methods for stubbing. Example:
 *
 * <pre class="code"><code class="java">
 *   List list = new LinkedList();
 *   List spy = spy(list);
 *
 *   //Impossible: real method is called so spy.get(0) throws IndexOutOfBoundsException (the list is yet empty)
 *   when(spy.get(0)).thenReturn("foo");
 *
 *   //You have to use doReturn() for stubbing
 *   doReturn("foo").when(spy).get(0);
 * </code></pre>
 * </li>
 *
 * <li>Mockito <b>*does not*</b> delegate calls to the passed real instance, instead it actually creates a copy of it.
 * So if you keep the real instance and interact with it, don't expect the spied to be aware of those interaction
 * and their effect on real instance state.
 * The corollary is that when an <b>*unstubbed*</b> method is called <b>*on the spy*</b> but <b>*not on the real instance*</b>,
 * you won't see any effects on the real instance.
 * </li>
 *
 * <li>Watch out for final methods.
 * Mockito doesn't mock final methods so the bottom line is: when you spy on real objects + you try to stub a final method = trouble.
 * Also you won't be able to verify those method as well.
 * </li>
 * </ol>
 *
 *
 *
 *
 * <h3 id="14">14. Changing <a class="meaningful_link" href="#defaultreturn">default return values of unstubbed invocations</a> (Since 1.7)</h3>
 *
 * You can create a mock with specified strategy for its return values.
 * It's quite advanced feature and typically you don't need it to write decent tests.
 * However, it can be helpful for working with <b>legacy systems</b>.
 * <p>
 * It is the default answer so it will be used <b>only when you don't</b> stub the method call.
 *
 * <pre class="code"><code class="java">
 *   Foo mock = mock(Foo.class, Mockito.RETURNS_SMART_NULLS);
 *   Foo mockTwo = mock(Foo.class, new YourOwnAnswer());
 * </code></pre>
 *
 * <p>
 * Read more about this interesting implementation of <i>Answer</i>: {@link Mockito#RETURNS_SMART_NULLS}
 *
 *
 *
 *
 * <h3 id="15">15. <a class="meaningful_link" href="#captors">Capturing arguments</a> for further assertions (Since 1.8.0)</h3>
 *
 * Mockito verifies argument values in natural java style: by using an <code>equals()</code> method.
 * This is also the recommended way of matching arguments because it makes tests clean & simple.
 * In some situations though, it is helpful to assert on certain arguments after the actual verification.
 * For example:
 * <pre class="code"><code class="java">
 *   ArgumentCaptor&lt;Person&gt; argument = ArgumentCaptor.forClass(Person.class);
 *   verify(mock).doSomething(argument.capture());
 *   assertEquals("John", argument.getValue().getName());
 * </code></pre>
 *
 * <b>Warning:</b> it is recommended to use ArgumentCaptor with verification <b>but not</b> with stubbing.
 * Using ArgumentCaptor with stubbing may decrease test readability because captor is created outside of assert (aka verify or 'then') block.
 * Also it may reduce defect localization because if stubbed method was not called then no argument is captured.
 * <p>
 * In a way ArgumentCaptor is related to custom argument matchers (see javadoc for {@link ArgumentMatcher} class).
 * Both techniques can be used for making sure certain arguments where passed to mocks.
 * However, ArgumentCaptor may be a better fit if:
 * <ul>
 * <li>custom argument matcher is not likely to be reused</li>
 * <li>you just need it to assert on argument values to complete verification</li>
 * </ul>
 * Custom argument matchers via {@link ArgumentMatcher} are usually better for stubbing.
 *
 *
 *
 *
 * <h3 id="16">16. <a class="meaningful_link" href="#partial_mocks">Real partial mocks</a> (Since 1.8.0)</h3>
 *
 *  Finally, after many internal debates & discussions on the mailing list, partial mock support was added to Mockito.
 *  Previously we considered partial mocks as code smells. However, we found a legitimate use case for partial mocks - more reading:
 *  <a href="http://monkeyisland.pl/2009/01/13/subclass-and-override-vs-partial-mocking-vs-refactoring">here</a>
 *  <p>
 *  <b>Before release 1.8</b> <code>spy()</code> was not producing real partial mocks and it was confusing for some users.
 *  Read more about spying: <a href="#13">here</a> or in javadoc for {@link Mockito#spy(Object)} method.
 *  <p>
 *  <pre class="code"><code class="java">
 *    //you can create partial mock with spy() method:
 *    List list = spy(new LinkedList());
 *
 *    //you can enable partial mock capabilities selectively on mocks:
 *    Foo mock = mock(Foo.class);
 *    //Be sure the real implementation is 'safe'.
 *    //If real implementation throws exceptions or depends on specific state of the object then you're in trouble.
 *    when(mock.someMethod()).thenCallRealMethod();
 *  </code></pre>
 *
 * As usual you are going to read <b>the partial mock warning</b>:
 * Object oriented programming is more less tackling complexity by dividing the complexity into separate, specific, SRPy objects.
 * How does partial mock fit into this paradigm? Well, it just doesn't...
 * Partial mock usually means that the complexity has been moved to a different method on the same object.
 * In most cases, this is not the way you want to design your application.
 * <p>
 * However, there are rare cases when partial mocks come handy:
 * dealing with code you cannot change easily (3rd party interfaces, interim refactoring of legacy code etc.)
 * However, I wouldn't use partial mocks for new, test-driven & well-designed code.
 *
 *
 *
 *
 * <h3 id="17">17. <a class="meaningful_link" href="#resetting_mocks">Resetting mocks</a> (Since 1.8.0)</h3>
 *
 * Smart Mockito users hardly use this feature because they know it could be a sign of poor tests.
 * Normally, you don't need to reset your mocks, just create new mocks for each test method.
 * <p>
 * Instead of <code>reset()</code> please consider writing simple, small and focused test methods over lengthy, over-specified tests.
 * <b>First potential code smell is <code>reset()</code> in the middle of the test method.</b> This probably means you're testing too much.
 * Follow the whisper of your test methods: "Please keep us small & focused on single behavior".
 * There are several threads about it on mockito mailing list.
 * <p>
 * The only reason we added <code>reset()</code> method is to
 * make it possible to work with container-injected mocks.
 * See issue 55 (<a href="http://code.google.com/p/mockito/issues/detail?id=55">here</a>)
 * or FAQ (<a href="http://code.google.com/p/mockito/wiki/FAQ">here</a>).
 * <p>
 * <b>Don't harm yourself.</b> <code>reset()</code> in the middle of the test method is a code smell (you're probably testing too much).
 * <pre class="code"><code class="java">
 *   List mock = mock(List.class);
 *   when(mock.size()).thenReturn(10);
 *   mock.add(1);
 *
 *   reset(mock);
 *   //at this point the mock forgot any interactions & stubbing
 * </code></pre>
 *
 *
 *
 *
 * <h3 id="18">18. <a class="meaningful_link" href="#framework_validation">Troubleshooting & validating framework usage</a> (Since 1.8.0)</h3>
 *
 * First of all, in case of any trouble, I encourage you to read the Mockito FAQ:
 * <a href="http://code.google.com/p/mockito/wiki/FAQ">http://code.google.com/p/mockito/wiki/FAQ</a>
 * <p>
 * In case of questions you may also post to mockito mailing list:
 * <a href="http://groups.google.com/group/mockito">http://groups.google.com/group/mockito</a>
 * <p>
 * Next, you should know that Mockito validates if you use it correctly <b>all the time</b>.
 * However, there's a gotcha so please read the javadoc for {@link Mockito#validateMockitoUsage()}
 *
 *
 *
 *
 * <h3 id="19">19. <a class="meaningful_link" href="#bdd_mockito">Aliases for behavior driven development</a> (Since 1.8.0)</h3>
 *
 * Behavior Driven Development style of writing tests uses <b>//given //when //then</b> comments as fundamental parts of your test methods.
 * This is exactly how we write our tests and we warmly encourage you to do so!
 * <p>
 * Start learning about BDD here: <a href="http://en.wikipedia.org/wiki/Behavior_Driven_Development">http://en.wikipedia.org/wiki/Behavior_Driven_Development</a>
 * <p>
 * The problem is that current stubbing api with canonical role of <b>when</b> word does not integrate nicely with <b>//given //when //then</b> comments.
 * It's because stubbing belongs to <b>given</b> component of the test and not to the <b>when</b> component of the test.
 * Hence {@link BDDMockito} class introduces an alias so that you stub method calls with {@link BDDMockito#given(Object)} method.
 * Now it really nicely integrates with the <b>given</b> component of a BDD style test!
 * <p>
 * Here is how the test might look like:
 * <pre class="code"><code class="java">
 * import static org.mockito.BDDMockito.*;
 *
 * Seller seller = mock(Seller.class);
 * Shop shop = new Shop(seller);
 *
 * public void shouldBuyBread() throws Exception {
 *   //given
 *   given(seller.askForBread()).willReturn(new Bread());
 *
 *   //when
 *   Goods goods = shop.buyBread();
 *
 *   //then
 *   assertThat(goods, containBread());
 * }
 * </code></pre>
 *
 *
 *
 *
 * <h3 id="20">20. <a class="meaningful_link" href="#serializable_mocks">Serializable mocks</a> (Since 1.8.1)</h3>
 *
 * Mocks can be made serializable. With this feature you can use a mock in a place that requires dependencies to be serializable.
 * <p>
 * WARNING: This should be rarely used in unit testing.
 * <p>
 * The behaviour was implemented for a specific use case of a BDD spec that had an unreliable external dependency.  This
 * was in a web environment and the objects from the external dependency were being serialized to pass between layers.
 * <p>
 * To create serializable mock use {@link MockSettings#serializable()}:
 * <pre class="code"><code class="java">
 *   List serializableMock = mock(List.class, withSettings().serializable());
 * </code></pre>
 * <p>
 * The mock can be serialized assuming all the normal <a href='http://java.sun.com/j2se/1.5.0/docs/api/java/io/Serializable.html'>
 * serialization requirements</a> are met by the class.
 * <p>
 * Making a real object spy serializable is a bit more effort as the spy(...) method does not have an overloaded version
 * which accepts MockSettings. No worries, you will hardly ever use it.
 *
 * <pre class="code"><code class="java">
 * List&lt;Object&gt; list = new ArrayList&lt;Object&gt;();
 * List&lt;Object&gt; spy = mock(ArrayList.class, withSettings()
 *                 .spiedInstance(list)
 *                 .defaultAnswer(CALLS_REAL_METHODS)
 *                 .serializable());
 * </code></pre>
 *
 *
 *
 *
 * <h3 id="21">21. New annotations: <a class="meaningful_link" href="#captor_annotation"><code>&#064;Captor</code></a>,
 * <a class="meaningful_link" href="#spy_annotation"><code>&#064;Spy</code></a>,
 * <a class="meaningful_link" href="#injectmocks_annotation"><code>&#064;InjectMocks</code></a> (Since 1.8.3)</h3>
 *
 * <p>
 * Release 1.8.3 brings new annotations that may be helpful on occasion:
 *
 * <ul>
 * <li>&#064;{@link Captor} simplifies creation of {@link ArgumentCaptor}
 * - useful when the argument to capture is a nasty generic class and you want to avoid compiler warnings
 * <li>&#064;{@link Spy} - you can use it instead {@link Mockito#spy(Object)}.
 * <li>&#064;{@link InjectMocks} - injects mock or spy fields into tested object automatically.
 * </ul>
 *
 * <p>
 * Note that &#064;{@link InjectMocks} can only be used in combination with the &#064;{@link Spy} annotation, it means
 * that Mockito will inject mocks in a partial mock under testing. As a remainder, please read point 16 about partial mocks.
 *
 * <p>
 * All new annotations are <b>*only*</b> processed on {@link MockitoAnnotations#initMocks(Object)}.
 * Just like for &#064;{@link Mock} annotation you can use the built-in runner: {@link MockitoJUnitRunner}.
 * <p>
 *
 *
 *
 *
 * <h3 id="22">22. <a class="meaningful_link" href="#verification_timeout">Verification with timeout</a> (Since 1.8.5)</h3>
 * <p>
 * Allows verifying with timeout. It causes a verify to wait for a specified period of time for a desired
 * interaction rather than fails immediately if had not already happened. May be useful for testing in concurrent
 * conditions.
 * <p>
 * It feels this feature should be used rarely - figure out a better way of testing your multi-threaded system.
 * <p>
 * Not yet implemented to work with InOrder verification.
 * <p>
 * Examples:
 * <p>
 * <pre class="code"><code class="java">
 *   //passes when someMethod() is called within given time span
 *   verify(mock, timeout(100)).someMethod();
 *   //above is an alias to:
 *   verify(mock, timeout(100).times(1)).someMethod();
 *
 *   //passes when someMethod() is called <b>*exactly*</b> 2 times within given time span
 *   verify(mock, timeout(100).times(2)).someMethod();
 *
 *   //passes when someMethod() is called <b>*at least*</b> 2 times within given time span
 *   verify(mock, timeout(100).atLeast(2)).someMethod();
 *
 *   //verifies someMethod() within given time span using given verification mode
 *   //useful only if you have your own custom verification modes.
 *   verify(mock, new Timeout(100, yourOwnVerificationMode)).someMethod();
 * </code></pre>
 *
 *
 *
 *
 * <h3 id="23">23. (New) <a class="meaningful_link" href="#automatic_instantiation">Automatic instantiation of <code>&#064;Spies</code>,
 * <code>&#064;InjectMocks</code></a> and <a class="meaningful_link" href="#constructor_injection">constructor injection goodness</a> (Since 1.9.0)</h3>
 *
 * <p>
 * Mockito will now try to instantiate &#064;{@link Spy} and will instantiate &#064;{@link InjectMocks} fields
 * using <b>constructor</b> injection, <b>setter</b> injection, or <b>field</b> injection.
 * <p>
 * To take advantage of this feature you need to use {@link MockitoAnnotations#initMocks(Object)} or {@link MockitoJUnitRunner}.
 * <p>
 * Read more about available tricks and the rules of injection in the javadoc for {@link InjectMocks}
 * <pre class="code"><code class="java">
 * //instead:
 * &#064;Spy BeerDrinker drinker = new BeerDrinker();
 * //you can write:
 * &#064;Spy BeerDrinker drinker;
 *
 * //same applies to &#064;InjectMocks annotation:
 * &#064;InjectMocks LocalPub;
 * </code></pre>
 *
 *
 *
 *
 * <h3 id="24">24. (New) <a class="meaningful_link" href="#one_liner_stub">One-liner stubs</a> (Since 1.9.0)</h3>
 * <p>
 * Mockito will now allow you to create mocks when stubbing.
 * Basically, it allows to create a stub in one line of code.
 * This can be helpful to keep test code clean.
 * For example, some boring stub can be created & stubbed at field initialization in a test:
 * <pre class="code"><code class="java">
 * public class CarTest {
 *   Car boringStubbedCar = when(mock(Car.class).shiftGear()).thenThrow(EngineNotStarted.class).getMock();
 *
 *   &#064;Test public void should... {}
 * </code></pre>
 *
 *
 *
 *
 * <h3 id="25">25. (New) <a class="meaningful_link" href="#ignore_stubs_verification">Verification ignoring stubs</a> (Since 1.9.0)</h3>
 * <p>
 * Mockito will now allow to ignore stubbing for the sake of verification.
 * Sometimes useful when coupled with <code>verifyNoMoreInteractions()</code> or verification <code>inOrder()</code>.
 * Helps avoiding redundant verification of stubbed calls - typically we're not interested in verifying stubs.
 * <p>
 * <b>Warning</b>, <code>ignoreStubs()</code> might lead to overuse of verifyNoMoreInteractions(ignoreStubs(...));
 * Bear in mind that Mockito does not recommend bombarding every test with <code>verifyNoMoreInteractions()</code>
 * for the reasons outlined in javadoc for {@link Mockito#verifyNoMoreInteractions(Object...)}
 * <p>Some examples:
 * <pre class="code"><code class="java">
 * verify(mock).foo();
 * verify(mockTwo).bar();
 *
 * //ignores all stubbed methods:
 * verifyNoMoreInvocations(ignoreStubs(mock, mockTwo));
 *
 * //creates InOrder that will ignore stubbed
 * InOrder inOrder = inOrder(ignoreStubs(mock, mockTwo));
 * inOrder.verify(mock).foo();
 * inOrder.verify(mockTwo).bar();
 * inOrder.verifyNoMoreInteractions();
 * </code></pre>
 * <p>
 * Advanced examples and more details can be found in javadoc for {@link Mockito#ignoreStubs(Object...)}
 *
 *
 *
 *
 * <h3 id="26">26. (**New**) <a class="meaningful_link" href="#mocking_details">Mocking details</a> (Since 1.9.5)</h3>
 * <p>
 * To identify whether a particular object is a mock or a spy:
 * <pre class="code"><code class="java">
 *     Mockito.mockingDetails(someObject).isMock();
 *     Mockito.mockingDetails(someObject).isSpy();
 * </code></pre>
 * Both the {@link MockingDetails#isMock} and {@link MockingDetails#isSpy()} methods return <code>boolean</code>.
 * As a spy is just a different kind of mock, <code>isMock()</code> returns true if the object is a spy.
 * In future Mockito versions MockingDetails may grow and provide other useful information about the mock,
 * e.g. invocations, stubbing info, etc.
 *
 *
 *
 *
 * <h3 id="27">27. (**New**) <a class="meaningful_link" href="#delegating_call_to_real_instance">Delegate calls to real instance</a> (Since 1.9.5)</h3>
 *
 * <p>Useful for spies or partial mocks of objects <strong>that are difficult to mock or spy</strong> using the usual spy API.
 * Possible use cases:
 * <ul>
 *     <li>Final classes but with an interface</li>
 *     <li>Already custom proxied object</li>
 *     <li>Special objects with a finalize method, i.e. to avoid executing it 2 times</li>
 * </ul>
 *
 * <p>The difference with the regular spy:
 * <ul>
 *   <li>
 *     The regular spy ({@link #spy(Object)}) contains <strong>all</strong> state from the spied instance
 *     and the methods are invoked on the spy. The spied instance is only used at mock creation to copy the state from.
 *     If you call a method on a regular spy and it internally calls other methods on this spy, those calls are remembered
 *     for verifications, and they can be effectively stubbed.
 *   </li>
 *   <li>
 *     The mock that delegates simply delegates all methods to the delegate.
 *     The delegate is used all the time as methods are delegated onto it.
 *     If you call a method on a mock that delegates and it internally calls other methods on this mock,
 *     those calls are <strong>not</strong> remembered for verifications, stubbing does not have effect on them, too.
 *     Mock that delegates is less powerful than the regular spy but it is useful when the regular spy cannot be created.
 *   </li>
 * </ul>
 *
 * <p>
 * See more information in docs for {@link AdditionalAnswers#delegatesTo(Object)}.
 *
 *
 *
 *
 * <h3 id="28">28. (**New**) <a class="meaningful_link" href="#mock_maker_plugin"><code>MockMaker</code> API</a> (Since 1.9.5)</h3>
 * <p>Driven by requirements and patches from Google Android guys Mockito now offers an extension point
 *   that allows replacing the proxy generation engine. By default, Mockito uses cglib to create dynamic proxies.
 * <p>The extension point is for advanced users that want to extend Mockito. For example, it is now possible
 *   to use Mockito for Android testing with a help of dexmaker.
 * <p>For more details, motivations and examples please refer to
 * the docs for {@link org.mockito.plugins.MockMaker}.
 *
 */
@SuppressWarnings("unchecked")
public class Mockito extends Matchers {

    static final MockitoCore MOCKITO_CORE = new MockitoCore();

    /**
     * The default <code>Answer</code> of every mock <b>if</b> the mock was not stubbed.
     * Typically it just returns some empty value.
     * <p>
     * {@link Answer} can be used to define the return values of unstubbed invocations.
     * <p>
     * This implementation first tries the global configuration.
     * If there is no global configuration then it uses {@link ReturnsEmptyValues} (returns zeros, empty collections, nulls, etc.)
     */
    public static final Answer<Object> RETURNS_DEFAULTS = Answers.RETURNS_DEFAULTS.get();

    /**
     * Optional <code>Answer</code> to be used with {@link Mockito#mock(Class, Answer)}.
     * <p>
     * {@link Answer} can be used to define the return values of unstubbed invocations.
     * <p>
     * This implementation can be helpful when working with legacy code.
     * Unstubbed methods often return null. If your code uses the object returned by an unstubbed call you get a NullPointerException.
     * This implementation of Answer <b>returns SmartNull instead of null</b>.
     * <code>SmartNull</code> gives nicer exception message than NPE because it points out the line where unstubbed method was called. You just click on the stack trace.
     * <p>
     * <code>ReturnsSmartNulls</code> first tries to return ordinary return values (see {@link ReturnsMoreEmptyValues})
     * then it tries to return SmartNull. If the return type is final then plain null is returned.
     * <p>
     * <code>ReturnsSmartNulls</code> will be probably the default return values strategy in Mockito 2.0.
     * <p>
     * Example:
     * <pre class="code"><code class="java">
     *   Foo mock = (Foo.class, RETURNS_SMART_NULLS);
     *
     *   //calling unstubbed method here:
     *   Stuff stuff = mock.getStuff();
     *
     *   //using object returned by unstubbed call:
     *   stuff.doSomething();
     *
     *   //Above doesn't yield NullPointerException this time!
     *   //Instead, SmartNullPointerException is thrown.
     *   //Exception's cause links to unstubbed <i>mock.getStuff()</i> - just click on the stack trace.
     * </code></pre>
     */
    public static final Answer<Object> RETURNS_SMART_NULLS = Answers.RETURNS_SMART_NULLS.get();

    /**
     * Optional <code>Answer</code> to be used with {@link Mockito#mock(Class, Answer)}
     * <p>
     * {@link Answer} can be used to define the return values of unstubbed invocations.
     * <p>
     * This implementation can be helpful when working with legacy code.
     * <p>
     * ReturnsMocks first tries to return ordinary return values (see {@link ReturnsMoreEmptyValues})
     * then it tries to return mocks. If the return type cannot be mocked (e.g. is final) then plain null is returned.
     * <p>
     */
    public static final Answer<Object> RETURNS_MOCKS = Answers.RETURNS_MOCKS.get();

    /**
     * Optional <code>Answer</code> to be used with {@link Mockito#mock(Class, Answer)}.
     * <p>
     * Example that shows how deep stub works:
     * <pre class="code"><code class="java">
     *   Foo mock = mock(Foo.class, RETURNS_DEEP_STUBS);
     *
     *   // note that we're stubbing a chain of methods here: getBar().getName()
     *   when(mock.getBar().getName()).thenReturn("deep");
     *
     *   // note that we're chaining method calls: getBar().getName()
     *   assertEquals("deep", mock.getBar().getName());
     * </code></pre>
     * </p>
     *
     * <p>
     * <strong>WARNING: </strong>
     * This feature should rarely be required for regular clean code! Leave it for legacy code.
     * Mocking a mock to return a mock, to return a mock, (...), to return something meaningful
     * hints at violation of Law of Demeter or mocking a value object (a well known anti-pattern).
     * </p>
     *
     * <p>
     * Good quote I've seen one day on the web: <strong>every time a mock returns a mock a fairy dies</strong>.
     * </p>
     *
     * <p>
     * Please note that this answer will return existing mocks that matches the stub. This
     * behavior is ok with deep stubs and allows verification to work on the last mock of the chain.
     * <pre class="code"><code class="java">
     *   when(mock.getBar(anyString()).getThingy().getName()).thenReturn("deep");
     *
     *   mock.getBar("candy bar").getThingy().getName();
     *
     *   assertSame(mock.getBar(anyString()).getThingy().getName(), mock.getBar(anyString()).getThingy().getName());
     *   verify(mock.getBar("candy bar").getThingy()).getName();
     *   verify(mock.getBar(anyString()).getThingy()).getName();
     * </code></pre>
     * </p>
     *
     * <p>
     * Verification only works with the last mock in the chain. You can use verification modes.
     * <pre class="code"><code class="java">
     *   when(person.getAddress(anyString()).getStreet().getName()).thenReturn("deep");
     *   when(person.getAddress(anyString()).getStreet(Locale.ITALIAN).getName()).thenReturn("deep");
     *   when(person.getAddress(anyString()).getStreet(Locale.CHINESE).getName()).thenReturn("deep");
     *
     *   person.getAddress("the docks").getStreet().getName();
     *   person.getAddress("the docks").getStreet().getLongName();
     *   person.getAddress("the docks").getStreet(Locale.ITALIAN).getName();
     *   person.getAddress("the docks").getStreet(Locale.CHINESE).getName();
     *
     *   // note that we are actually referring to the very last mock in the stubbing chain.
     *   InOrder inOrder = inOrder(
     *       person.getAddress("the docks").getStreet(),
     *       person.getAddress("the docks").getStreet(Locale.CHINESE),
     *       person.getAddress("the docks").getStreet(Locale.ITALIAN)
     *   );
     *   inOrder.verify(person.getAddress("the docks").getStreet(), times(1)).getName();
     *   inOrder.verify(person.getAddress("the docks").getStreet()).getLongName();
     *   inOrder.verify(person.getAddress("the docks").getStreet(Locale.ITALIAN), atLeast(1)).getName();
     *   inOrder.verify(person.getAddress("the docks").getStreet(Locale.CHINESE)).getName();
     * </code></pre>
     * </p>
     *
     * <p>
     * How deep stub work internally?
     * <pre class="code"><code class="java">
     *   //this:
     *   Foo mock = mock(Foo.class, RETURNS_DEEP_STUBS);
     *   when(mock.getBar().getName(), "deep");
     *
     *   //is equivalent of
     *   Foo foo = mock(Foo.class);
     *   Bar bar = mock(Bar.class);
     *   when(foo.getBar()).thenReturn(bar);
     *   when(bar.getName()).thenReturn("deep");
     * </code></pre>
     * </p>
     *
     * <p>
     * This feature will not work when any return type of methods included in the chain cannot be mocked
     * (for example: is a primitive or a final class). This is because of java type system.
     * </p>
     */
    public static final Answer<Object> RETURNS_DEEP_STUBS = Answers.RETURNS_DEEP_STUBS.get();

    /**
     * Optional <code>Answer</code> to be used with {@link Mockito#mock(Class, Answer)}
     * <p>
     * {@link Answer} can be used to define the return values of unstubbed invocations.
     * <p>
     * This implementation can be helpful when working with legacy code.
     * When this implementation is used, unstubbed methods will delegate to the real implementation.
     * This is a way to create a partial mock object that calls real methods by default.
     * <p>
     * As usual you are going to read <b>the partial mock warning</b>:
     * Object oriented programming is more less tackling complexity by dividing the complexity into separate, specific, SRPy objects.
     * How does partial mock fit into this paradigm? Well, it just doesn't...
     * Partial mock usually means that the complexity has been moved to a different method on the same object.
     * In most cases, this is not the way you want to design your application.
     * <p>
     * However, there are rare cases when partial mocks come handy:
     * dealing with code you cannot change easily (3rd party interfaces, interim refactoring of legacy code etc.)
     * However, I wouldn't use partial mocks for new, test-driven & well-designed code.
     * <p>
     * Example:
     * <pre class="code"><code class="java">
     * Foo mock = mock(Foo.class, CALLS_REAL_METHODS);
     *
     * // this calls the real implementation of Foo.getSomething()
     * value = mock.getSomething();
     *
     * when(mock.getSomething()).thenReturn(fakeValue);
     *
     * // now fakeValue is returned
     * value = mock.getSomething();
     * </code></pre>
     */
    public static final Answer<Object> CALLS_REAL_METHODS = Answers.CALLS_REAL_METHODS.get();

    /**
     * Creates mock object of given class or interface.
     * <p>
     * See examples in javadoc for {@link Mockito} class
     *
     * @param classToMock class or interface to mock
     * @return mock object
     */
    public static <T> T mock(Class<T> classToMock) {
        return mock(classToMock, withSettings().defaultAnswer(RETURNS_DEFAULTS));
    }

    /**
     * Specifies mock name. Naming mocks can be helpful for debugging - the name is used in all verification errors.
     * <p>
     * Beware that naming mocks is not a solution for complex code which uses too many mocks or collaborators.
     * <b>If you have too many mocks then refactor the code</b> so that it's easy to test/debug without necessity of naming mocks.
     * <p>
     * <b>If you use <code>&#064;Mock</code> annotation then you've got naming mocks for free!</b> <code>&#064;Mock</code> uses field name as mock name. {@link Mock Read more.}
     * <p>
     *
     * See examples in javadoc for {@link Mockito} class
     *
     * @param classToMock class or interface to mock
     * @param name of the mock
     * @return mock object
     */
    public static <T> T mock(Class<T> classToMock, String name) {
        return mock(classToMock, withSettings()
                .name(name)
                .defaultAnswer(RETURNS_DEFAULTS));
    }

    /**
     * Returns a MockingDetails instance that enables inspecting a particular object for Mockito related information.
     * Can be used to find out if given object is a Mockito mock
     * or to find out if a given mock is a spy or mock.
     * <p>
     * In future Mockito versions MockingDetails may grow and provide other useful information about the mock,
     * e.g. invocations, stubbing info, etc.
     *
     * @param toInspect - object to inspect
     * @return A {@link org.mockito.MockingDetails} instance.
     * @since 1.9.5
     */
    @Incubating
    public static MockingDetails mockingDetails(Object toInspect) {
        return MOCKITO_CORE.mockingDetails(toInspect);
    }

    /**
     * <b>Deprecated : Please use mock(Foo.class, defaultAnswer);</b>
     * <p>
     * See {@link Mockito#mock(Class, Answer)}
     * <p>
     * Why it is deprecated? ReturnValues is being replaced by Answer
     * for better consistency & interoperability of the framework.
     * Answer interface has been in Mockito for a while and it has the same responsibility as ReturnValues.
     * There's no point in mainting exactly the same interfaces.
     * <p>
     * Creates mock with a specified strategy for its return values.
     * It's quite advanced feature and typically you don't need it to write decent tests.
     * However it can be helpful when working with legacy systems.
     * <p>
     * Obviously return values are used only when you don't stub the method call.
     *
     * <pre class="code"><code class="java">
     *   Foo mock = mock(Foo.class, Mockito.RETURNS_SMART_NULLS);
     *   Foo mockTwo = mock(Foo.class, new YourOwnReturnValues());
     * </code></pre>
     *
     * <p>See examples in javadoc for {@link Mockito} class</p>
     *
     * @param classToMock class or interface to mock
     * @param returnValues default return values for unstubbed methods
     *
     * @return mock object
     *
     * @deprecated <b>Please use mock(Foo.class, defaultAnswer);</b>
     */
    @Deprecated
    public static <T> T mock(Class<T> classToMock, ReturnValues returnValues) {
        return mock(classToMock, withSettings().defaultAnswer(new AnswerReturnValuesAdapter(returnValues)));
    }

    /**
     * Creates mock with a specified strategy for its answers to interactions.
     * It's quite advanced feature and typically you don't need it to write decent tests.
     * However it can be helpful when working with legacy systems.
     * <p>
     * It is the default answer so it will be used <b>only when you don't</b> stub the method call.
     *
     * <pre class="code"><code class="java">
     *   Foo mock = mock(Foo.class, RETURNS_SMART_NULLS);
     *   Foo mockTwo = mock(Foo.class, new YourOwnAnswer());
     * </code></pre>
     *
     * <p>See examples in javadoc for {@link Mockito} class</p>
     *
     * @param classToMock class or interface to mock
     * @param defaultAnswer default answer for unstubbed methods
     *
     * @return mock object
     */
    public static <T> T mock(Class<T> classToMock, Answer defaultAnswer) {
        return mock(classToMock, withSettings().defaultAnswer(defaultAnswer));
    }

    /**
     * Creates a mock with some non-standard settings.
     * <p>
     * The number of configuration points for a mock grows
     * so we need a fluent way to introduce new configuration without adding more and more overloaded Mockito.mock() methods.
     * Hence {@link MockSettings}.
     * <pre class="code"><code class="java">
     *   Listener mock = mock(Listener.class, withSettings()
     *     .name("firstListner").defaultBehavior(RETURNS_SMART_NULLS));
     *   );
     * </code></pre>
     * <b>Use it carefully and occasionally</b>. What might be reason your test needs non-standard mocks?
     * Is the code under test so complicated that it requires non-standard mocks?
     * Wouldn't you prefer to refactor the code under test so it is testable in a simple way?
     * <p>
     * See also {@link Mockito#withSettings()}
     * <p>
     * See examples in javadoc for {@link Mockito} class
     *
     * @param classToMock class or interface to mock
     * @param mockSettings additional mock settings
     * @return mock object
     */
    public static <T> T mock(Class<T> classToMock, MockSettings mockSettings) {
        return MOCKITO_CORE.mock(classToMock, mockSettings);
    }

    /**
     * Creates a spy of the real object. The spy calls <b>real</b> methods unless they are stubbed.
     * <p>
     * Real spies should be used <b>carefully and occasionally</b>, for example when dealing with legacy code.
     * <p>
     * As usual you are going to read <b>the partial mock warning</b>:
     * Object oriented programming is more less tackling complexity by dividing the complexity into separate, specific, SRPy objects.
     * How does partial mock fit into this paradigm? Well, it just doesn't...
     * Partial mock usually means that the complexity has been moved to a different method on the same object.
     * In most cases, this is not the way you want to design your application.
     * <p>
     * However, there are rare cases when partial mocks come handy:
     * dealing with code you cannot change easily (3rd party interfaces, interim refactoring of legacy code etc.)
     * However, I wouldn't use partial mocks for new, test-driven & well-designed code.
     * <p>
     * Example:
     *
     * <pre class="code"><code class="java">
     *   List list = new LinkedList();
     *   List spy = spy(list);
     *
     *   //optionally, you can stub out some methods:
     *   when(spy.size()).thenReturn(100);
     *
     *   //using the spy calls <b>real</b> methods
     *   spy.add("one");
     *   spy.add("two");
     *
     *   //prints "one" - the first element of a list
     *   System.out.println(spy.get(0));
     *
     *   //size() method was stubbed - 100 is printed
     *   System.out.println(spy.size());
     *
     *   //optionally, you can verify
     *   verify(spy).add("one");
     *   verify(spy).add("two");
     * </code></pre>
     *
     * <h4>Important gotcha on spying real objects!</h4>
     * <ol>
     * <li>Sometimes it's impossible or impractical to use {@link Mockito#when(Object)} for stubbing spies.
     * Therefore for spies it is recommended to always use <code>doReturn</code>|<code>Answer</code>|<code>Throw()</code>|<code>CallRealMethod</code>
     * family of methods for stubbing. Example:
     *
     * <pre class="code"><code class="java">
     *   List list = new LinkedList();
     *   List spy = spy(list);
     *
     *   //Impossible: real method is called so spy.get(0) throws IndexOutOfBoundsException (the list is yet empty)
     *   when(spy.get(0)).thenReturn("foo");
     *
     *   //You have to use doReturn() for stubbing
     *   doReturn("foo").when(spy).get(0);
     * </code></pre>
     * </li>
     *
     * <li>Mockito <b>*does not*</b> delegate calls to the passed real instance, instead it actually creates a copy of it.
     * So if you keep the real instance and interact with it, don't expect the spied to be aware of those interaction
     * and their effect on real instance state.
     * The corollary is that when an <b>*unstubbed*</b> method is called <b>*on the spy*</b> but <b>*not on the real instance*</b>,
     * you won't see any effects on the real instance.</li>
     *
     * <li>Watch out for final methods.
     * Mockito doesn't mock final methods so the bottom line is: when you spy on real objects + you try to stub a final method = trouble.
     * Also you won't be able to verify those method as well.
     * </li>
     * </ol>
     * <p>
     * See examples in javadoc for {@link Mockito} class
     *
     * @param object
     *            to spy on
     * @return a spy of the real object
     */
    public static <T> T spy(T object) {
        return MOCKITO_CORE.mock((Class<T>) object.getClass(), withSettings()
                .spiedInstance(object)
                .defaultAnswer(CALLS_REAL_METHODS));
    }

    /**
     * Stubs a method call with return value or an exception. E.g:
     *
     * <pre class="code"><code class="java">
     * stub(mock.someMethod()).toReturn(10);
     *
     * //you can use flexible argument matchers, e.g:
     * stub(mock.someMethod(<b>anyString()</b>)).toReturn(10);
     *
     * //setting exception to be thrown:
     * stub(mock.someMethod("some arg")).toThrow(new RuntimeException());
     *
     * //you can stub with different behavior for consecutive method calls.
     * //Last stubbing (e.g: toReturn("foo")) determines the behavior for further consecutive calls.
     * stub(mock.someMethod("some arg"))
     *  .toThrow(new RuntimeException())
     *  .toReturn("foo");
     * </code></pre>
     * <p>
     * Some users find stub() confusing therefore {@link Mockito#when(Object)} is recommended over stub()
     * <pre class="code"><code class="java">
     *   //Instead of:
     *   stub(mock.count()).toReturn(10);
     *
     *   //You can do:
     *   when(mock.count()).thenReturn(10);
     * </code></pre>
     * For stubbing void methods with throwables see: {@link Mockito#doThrow(Throwable)}
     * <p>
     * Stubbing can be overridden: for example common stubbing can go to fixture
     * setup but the test methods can override it.
     * Please note that overridding stubbing is a potential code smell that points out too much stubbing.
     * <p>
     * Once stubbed, the method will always return stubbed value regardless
     * of how many times it is called.
     * <p>
     * Last stubbing is more important - when you stubbed the same method with
     * the same arguments many times.
     * <p>
     * Although it is possible to verify a stubbed invocation, usually <b>it's just redundant</b>.
     * Let's say you've stubbed foo.bar().
     * If your code cares what foo.bar() returns then something else breaks(often before even verify() gets executed).
     * If your code doesn't care what get(0) returns then it should not be stubbed.
     * Not convinced? See <a href="http://monkeyisland.pl/2008/04/26/asking-and-telling">here</a>.
     *
     * @param methodCall
     *            method call
     * @return DeprecatedOngoingStubbing object to set stubbed value/exception
     */
    public static <T> DeprecatedOngoingStubbing<T> stub(T methodCall) {
        return MOCKITO_CORE.stub(methodCall);
    }

    /**
     * Enables stubbing methods. Use it when you want the mock to return particular value when particular method is called.
     * <p>
     * Simply put: "<b>When</b> the x method is called <b>then</b> return y".
     * <p>
     * <b>when() is a successor of deprecated {@link Mockito#stub(Object)}</b>
     * <p>
     * Examples:
     *
     * <pre class="code"><code class="java">
     * <b>when</b>(mock.someMethod()).<b>thenReturn</b>(10);
     *
     * //you can use flexible argument matchers, e.g:
     * when(mock.someMethod(<b>anyString()</b>)).thenReturn(10);
     *
     * //setting exception to be thrown:
     * when(mock.someMethod("some arg")).thenThrow(new RuntimeException());
     *
     * //you can set different behavior for consecutive method calls.
     * //Last stubbing (e.g: thenReturn("foo")) determines the behavior of further consecutive calls.
     * when(mock.someMethod("some arg"))
     *  .thenThrow(new RuntimeException())
     *  .thenReturn("foo");
     *
     * //Alternative, shorter version for consecutive stubbing:
     * when(mock.someMethod("some arg"))
     *  .thenReturn("one", "two");
     * //is the same as:
     * when(mock.someMethod("some arg"))
     *  .thenReturn("one")
     *  .thenReturn("two");
     *
     * //shorter version for consecutive method calls throwing exceptions:
     * when(mock.someMethod("some arg"))
     *  .thenThrow(new RuntimeException(), new NullPointerException();
     *
     * </code></pre>
     *
     * For stubbing void methods with throwables see: {@link Mockito#doThrow(Throwable)}
     * <p>
     * Stubbing can be overridden: for example common stubbing can go to fixture
     * setup but the test methods can override it.
     * Please note that overridding stubbing is a potential code smell that points out too much stubbing.
     * <p>
     * Once stubbed, the method will always return stubbed value regardless
     * of how many times it is called.
     * <p>
     * Last stubbing is more important - when you stubbed the same method with
     * the same arguments many times.
     * <p>
     * Although it is possible to verify a stubbed invocation, usually <b>it's just redundant</b>.
     * Let's say you've stubbed <code>foo.bar()</code>.
     * If your code cares what <code>foo.bar()</code> returns then something else breaks(often before even <code>verify()</code> gets executed).
     * If your code doesn't care what <code>get(0)</code> returns then it should not be stubbed.
     * Not convinced? See <a href="http://monkeyisland.pl/2008/04/26/asking-and-telling">here</a>.
     *
     * <p>
     * See examples in javadoc for {@link Mockito} class
     * @param methodCall method to be stubbed
     * @return OngoingStubbing object used to stub fluently.
     *         <strong>Do not</strong> create a reference to this returned object.
     */
    public static <T> OngoingStubbing<T> when(T methodCall) {
        return MOCKITO_CORE.when(methodCall);
    }

    /**
     * Verifies certain behavior <b>happened once</b>.
     * <p>
     * Alias to <code>verify(mock, times(1))</code> E.g:
     * <pre class="code"><code class="java">
     *   verify(mock).someMethod("some arg");
     * </code></pre>
     * Above is equivalent to:
     * <pre class="code"><code class="java">
     *   verify(mock, times(1)).someMethod("some arg");
     * </code></pre>
     * <p>
     * Arguments passed are compared using <code>equals()</code> method.
     * Read about {@link ArgumentCaptor} or {@link ArgumentMatcher} to find out other ways of matching / asserting arguments passed.
     * <p>
     * Although it is possible to verify a stubbed invocation, usually <b>it's just redundant</b>.
     * Let's say you've stubbed <code>foo.bar()</code>.
     * If your code cares what <code>foo.bar()</code> returns then something else breaks(often before even <code>verify()</code> gets executed).
     * If your code doesn't care what <code>get(0)</code> returns then it should not be stubbed.
     * Not convinced? See <a href="http://monkeyisland.pl/2008/04/26/asking-and-telling">here</a>.
     *
     * <p>
     * See examples in javadoc for {@link Mockito} class
     *
     * @param mock to be verified
     * @return mock object itself
     */
    public static <T> T verify(T mock) {
        return MOCKITO_CORE.verify(mock, times(1));
    }

    /**
     * Verifies certain behavior happened at least once / exact number of times / never. E.g:
     * <pre class="code"><code class="java">
     *   verify(mock, times(5)).someMethod("was called five times");
     *
     *   verify(mock, atLeast(2)).someMethod("was called at least two times");
     *
     *   //you can use flexible argument matchers, e.g:
     *   verify(mock, atLeastOnce()).someMethod(<b>anyString()</b>);
     * </code></pre>
     *
     * <b>times(1) is the default</b> and can be omitted
     * <p>
     * Arguments passed are compared using <code>equals()</code> method.
     * Read about {@link ArgumentCaptor} or {@link ArgumentMatcher} to find out other ways of matching / asserting arguments passed.
     * <p>
     *
     * @param mock to be verified
     * @param mode times(x), atLeastOnce() or never()
     *
     * @return mock object itself
     */
    public static <T> T verify(T mock, VerificationMode mode) {
        return MOCKITO_CORE.verify(mock, mode);
    }

    /**
     * Smart Mockito users hardly use this feature because they know it could be a sign of poor tests.
     * Normally, you don't need to reset your mocks, just create new mocks for each test method.
     * <p>
     * Instead of <code>#reset()</code> please consider writing simple, small and focused test methods over lengthy, over-specified tests.
     * <b>First potential code smell is <code>reset()</code> in the middle of the test method.</b> This probably means you're testing too much.
     * Follow the whisper of your test methods: "Please keep us small & focused on single behavior".
     * There are several threads about it on mockito mailing list.
     * <p>
     * The only reason we added <code>reset()</code> method is to
     * make it possible to work with container-injected mocks.
     * See issue 55 (<a href="http://code.google.com/p/mockito/issues/detail?id=55">here</a>)
     * or FAQ (<a href="http://code.google.com/p/mockito/wiki/FAQ">here</a>).
     * <p>
     * <b>Don't harm yourself.</b> <code>reset()</code> in the middle of the test method is a code smell (you're probably testing too much).
     * <pre class="code"><code class="java">
     *   List mock = mock(List.class);
     *   when(mock.size()).thenReturn(10);
     *   mock.add(1);
     *
     *   reset(mock);
     *   //at this point the mock forgot any interactions & stubbing
     * </code></pre>
     *
     * @param <T> The Type of the mocks
     * @param mocks to be reset
     */
    public static <T> void reset(T ... mocks) {
        MOCKITO_CORE.reset(mocks);
    }

    /**
     * Checks if any of given mocks has any unverified interaction.
     * <p>
     * You can use this method after you verified your mocks - to make sure that nothing
     * else was invoked on your mocks.
     * <p>
     * See also {@link Mockito#never()} - it is more explicit and communicates the intent well.
     * <p>
     * Stubbed invocations (if called) are also treated as interactions.
     * <p>
     * A word of <b>warning</b>:
     * Some users who did a lot of classic, expect-run-verify mocking tend to use <code>verifyNoMoreInteractions()</code> very often, even in every test method.
     * <code>verifyNoMoreInteractions()</code> is not recommended to use in every test method.
     * <code>verifyNoMoreInteractions()</code> is a handy assertion from the interaction testing toolkit. Use it only when it's relevant.
     * Abusing it leads to overspecified, less maintainable tests. You can find further reading
     * <a href="http://monkeyisland.pl/2008/07/12/should-i-worry-about-the-unexpected/">here</a>.
     * <p>
     * This method will also detect unverified invocations that occurred before the test method,
     * for example: in <code>setUp()</code>, <code>&#064;Before</code> method or in constructor.
     * Consider writing nice code that makes interactions only in test methods.
     *
     * <p>
     * Example:
     *
     * <pre class="code"><code class="java">
     * //interactions
     * mock.doSomething();
     * mock.doSomethingUnexpected();
     *
     * //verification
     * verify(mock).doSomething();
     *
     * //following will fail because 'doSomethingUnexpected()' is unexpected
     * verifyNoMoreInteractions(mock);
     *
     * </code></pre>
     *
     * See examples in javadoc for {@link Mockito} class
     *
     * @param mocks to be verified
     */
    public static void verifyNoMoreInteractions(Object... mocks) {
        MOCKITO_CORE.verifyNoMoreInteractions(mocks);
    }

    /**
     * Verifies that no interactions happened on given mocks.
     * <pre class="code"><code class="java">
     *   verifyZeroInteractions(mockOne, mockTwo);
     * </code></pre>
     * This method will also detect invocations
     * that occurred before the test method, for example: in <code>setUp()</code>, <code>&#064;Before</code> method or in constructor.
     * Consider writing nice code that makes interactions only in test methods.
     * <p>
     * See also {@link Mockito#never()} - it is more explicit and communicates the intent well.
     * <p>
     * See examples in javadoc for {@link Mockito} class
     *
     * @param mocks to be verified
     */
    public static void verifyZeroInteractions(Object... mocks) {
        MOCKITO_CORE.verifyNoMoreInteractions(mocks);
    }

    /**
     * <pre class="code"><code class="java">
     *   //Instead of:
     *   stubVoid(mock).toThrow(e).on().someVoidMethod();
     *
     *   //Please do:
     *   doThrow(e).when(mock).someVoidMethod();
     * </code></pre>
     *
     * doThrow() replaces stubVoid() because of improved readability and consistency with the family of doAnswer() methods.
     * <p>
     * Originally, <code>stubVoid()</code> was used for stubbing void methods with exceptions. E.g:
     *
     * <pre class="code"><code class="java">
     * stubVoid(mock).toThrow(new RuntimeException()).on().someMethod();
     *
     * //you can stub with different behavior for consecutive calls.
     * //Last stubbing (e.g. toReturn()) determines the behavior for further consecutive calls.
     * stubVoid(mock)
     *   .toThrow(new RuntimeException())
     *   .toReturn()
     *   .on().someMethod();
     * </code></pre>
     *
     * See examples in javadoc for {@link Mockito} class
     *
     * @deprecated Use {@link Mockito#doThrow(Throwable)} method for stubbing voids
     *
     * @param mock
     *            to stub
     * @return stubbable object that allows stubbing with throwable
     */
    public static <T> VoidMethodStubbable<T> stubVoid(T mock) {
        return MOCKITO_CORE.stubVoid(mock);
    }

    /**
     * Use <code>doThrow()</code> when you want to stub the void method with an exception.
     * <p>
     * Stubbing voids requires different approach from {@link Mockito#when(Object)} because the compiler does not like void methods inside brackets...
     * <p>
     * Example:
     *
     * <pre class="code"><code class="java">
     *   doThrow(new RuntimeException()).when(mock).someVoidMethod();
     * </code></pre>
     *
     * @param toBeThrown to be thrown when the stubbed method is called
     * @return stubber - to select a method for stubbing
     */
    public static Stubber doThrow(Throwable toBeThrown) {
        return MOCKITO_CORE.doAnswer(new ThrowsException(toBeThrown));
    }

    /**
     * Use <code>doThrow()</code> when you want to stub the void method to throw exception of specified class.
     * <p>
     * A new exception instance will be created for each method invocation.
     * <p>
     * Stubbing voids requires different approach from {@link Mockito#when(Object)} because the compiler does not like void methods inside brackets...
     * <p>
     * Example:
     *
     * <pre class="code"><code class="java">
     *   doThrow(RuntimeException.class).when(mock).someVoidMethod();
     * </code></pre>
     *
     * @param toBeThrown to be thrown when the stubbed method is called
     * @return stubber - to select a method for stubbing
     * @since 1.9.0
     */
    public static Stubber doThrow(Class<? extends Throwable> toBeThrown) {
        return MOCKITO_CORE.doAnswer(new ThrowsExceptionClass(toBeThrown));
    }


    /**
     * Use <code>doCallRealMethod()</code> when you want to call the real implementation of a method.
     * <p>
     * As usual you are going to read <b>the partial mock warning</b>:
     * Object oriented programming is more less tackling complexity by dividing the complexity into separate, specific, SRPy objects.
     * How does partial mock fit into this paradigm? Well, it just doesn't...
     * Partial mock usually means that the complexity has been moved to a different method on the same object.
     * In most cases, this is not the way you want to design your application.
     * <p>
     * However, there are rare cases when partial mocks come handy:
     * dealing with code you cannot change easily (3rd party interfaces, interim refactoring of legacy code etc.)
     * However, I wouldn't use partial mocks for new, test-driven & well-designed code.
     * <p>
     * See also javadoc {@link Mockito#spy(Object)} to find out more about partial mocks.
     * <b>Mockito.spy() is a recommended way of creating partial mocks.</b>
     * The reason is it guarantees real methods are called against correctly constructed object because you're responsible for constructing the object passed to spy() method.
     * <p>
     * Example:
     * <pre class="code"><code class="java">
     *   Foo mock = mock(Foo.class);
     *   doCallRealMethod().when(mock).someVoidMethod();
     *
     *   // this will call the real implementation of Foo.someVoidMethod()
     *   mock.someVoidMethod();
     * </code></pre>
     * <p>
     * See examples in javadoc for {@link Mockito} class
     *
     * @return stubber - to select a method for stubbing
     * @since 1.9.5
     */
    public static Stubber doCallRealMethod() {
        return MOCKITO_CORE.doAnswer(new CallsRealMethods());
    }

    /**
     * Use <code>doAnswer()</code> when you want to stub a void method with generic {@link Answer}.
     * <p>
     * Stubbing voids requires different approach from {@link Mockito#when(Object)} because the compiler does not like void methods inside brackets...
     * <p>
     * Example:
     *
     * <pre class="code"><code class="java">
     *  doAnswer(new Answer() {
     *      public Object answer(InvocationOnMock invocation) {
     *          Object[] args = invocation.getArguments();
     *          Mock mock = invocation.getMock();
     *          return null;
     *      }})
     *  .when(mock).someMethod();
     * </code></pre>
     * <p>
     * See examples in javadoc for {@link Mockito} class
     *
     * @param answer to answer when the stubbed method is called
     * @return stubber - to select a method for stubbing
     */
    public static Stubber doAnswer(Answer answer) {
        return MOCKITO_CORE.doAnswer(answer);
    }

    /**
     * Use <code>doNothing()</code> for setting void methods to do nothing. <b>Beware that void methods on mocks do nothing by default!</b>
     * However, there are rare situations when doNothing() comes handy:
     * <p>
     * <ol>
     * <li>Stubbing consecutive calls on a void method:
     * <pre class="code"><code class="java">
     *   doNothing().
     *   doThrow(new RuntimeException())
     *   .when(mock).someVoidMethod();
     *
     *   //does nothing the first time:
     *   mock.someVoidMethod();
     *
     *   //throws RuntimeException the next time:
     *   mock.someVoidMethod();
     * </code></pre>
     * </li>
     * <li>When you spy real objects and you want the void method to do nothing:
     * <pre class="code"><code class="java">
     *   List list = new LinkedList();
     *   List spy = spy(list);
     *
     *   //let's make clear() do nothing
     *   doNothing().when(spy).clear();
     *
     *   spy.add("one");
     *
     *   //clear() does nothing, so the list still contains "one"
     *   spy.clear();
     * </code></pre>
     * </li>
     * </ol>
     * <p>
     * See examples in javadoc for {@link Mockito} class
     *
     * @return stubber - to select a method for stubbing
     */
    public static Stubber doNothing() {
        return MOCKITO_CORE.doAnswer(new DoesNothing());
    }

    /**
     * Use <code>doReturn()</code> in those rare occasions when you cannot use {@link Mockito#when(Object)}.
     * <p>
     * <b>Beware that {@link Mockito#when(Object)} is always recommended for stubbing because it is argument type-safe
     * and more readable</b> (especially when stubbing consecutive calls).
     * <p>
     * Here are those rare occasions when doReturn() comes handy:
     * <p>
     *
     * <ol>
     * <li>When spying real objects and calling real methods on a spy brings side effects
     *
     * <pre class="code"><code class="java">
     *   List list = new LinkedList();
     *   List spy = spy(list);
     *
     *   //Impossible: real method is called so spy.get(0) throws IndexOutOfBoundsException (the list is yet empty)
     *   when(spy.get(0)).thenReturn("foo");
     *
     *   //You have to use doReturn() for stubbing:
     *   doReturn("foo").when(spy).get(0);
     * </code></pre>
     * </li>
     *
     * <li>Overriding a previous exception-stubbing:
     * <pre class="code"><code class="java">
     *   when(mock.foo()).thenThrow(new RuntimeException());
     *
     *   //Impossible: the exception-stubbed foo() method is called so RuntimeException is thrown.
     *   when(mock.foo()).thenReturn("bar");
     *
     *   //You have to use doReturn() for stubbing:
     *   doReturn("bar").when(mock).foo();
     * </code></pre>
     * </li>
     * </ol>
     *
     * Above scenarios shows a tradeoff of Mockito's elegant syntax. Note that the scenarios are very rare, though.
     * Spying should be sporadic and overriding exception-stubbing is very rare. Not to mention that in general
     * overridding stubbing is a potential code smell that points out too much stubbing.
     * <p>
     * See examples in javadoc for {@link Mockito} class
     *
     * @param toBeReturned to be returned when the stubbed method is called
     * @return stubber - to select a method for stubbing
     */
    public static Stubber doReturn(Object toBeReturned) {
        return MOCKITO_CORE.doAnswer(new Returns(toBeReturned));
    }

    /**
     * Creates {@link org.mockito.InOrder} object that allows verifying mocks in order.
     *
     * <pre class="code"><code class="java">
     *   InOrder inOrder = inOrder(firstMock, secondMock);
     *
     *   inOrder.verify(firstMock).add("was called first");
     *   inOrder.verify(secondMock).add("was called second");
     * </code></pre>
     *
     * Verification in order is flexible - <b>you don't have to verify all interactions</b> one-by-one
     * but only those that you are interested in testing in order.
     * <p>
     * Also, you can create InOrder object passing only mocks that are relevant for in-order verification.
     * <p>
     * <code>InOrder</code> verification is 'greedy'. You will hardly every notice it but
     * if you want to find out more search for 'greedy' on the Mockito
     * <a href="http://code.google.com/p/mockito/w/list">wiki pages</a>.
     * <p>
     * As of Mockito 1.8.4 you can verifyNoMoreInvocations() in order-sensitive way. Read more: {@link InOrder#verifyNoMoreInteractions()}
     * <p>
     * See examples in javadoc for {@link Mockito} class
     *
     * @param mocks to be verified in order
     *
     * @return InOrder object to be used to verify in order
     */
    public static InOrder inOrder(Object... mocks) {
        return MOCKITO_CORE.inOrder(mocks);
    }

    /**
     * Ignores stubbed methods of given mocks for the sake of verification.
     * Sometimes useful when coupled with <code>verifyNoMoreInteractions()</code> or verification <code>inOrder()</code>.
     * Helps avoiding redundant verification of stubbed calls - typically we're not interested in verifying stubs.
     * <p>
     * <b>Warning</b>, <code>ignoreStubs()</code> might lead to overuse of <code>verifyNoMoreInteractions(ignoreStubs(...));</code>
     * Bear in mind that Mockito does not recommend bombarding every test with <code>verifyNoMoreInteractions()</code>
     * for the reasons outlined in javadoc for {@link Mockito#verifyNoMoreInteractions(Object...)}
     * Other words: all <b>*stubbed*</b> methods of given mocks are marked <b>*verified*</b> so that they don't get in a way during verifyNoMoreInteractions().
     * <p>
     * This method <b>changes the input mocks</b>! This method returns input mocks just for convenience.
     * <p>
     * Ignored stubs will also be ignored for verification inOrder, including {@link org.mockito.InOrder#verifyNoMoreInteractions()}.
     * See the second example.
     * <p>
     * Example:
     * <pre class="code"><code class="java">
     *  //mocking lists for the sake of the example (if you mock List in real you will burn in hell)
     *  List mock1 = mock(List.class), mock2 = mock(List.class);
     *
     *  //stubbing mocks:
     *  when(mock1.get(0)).thenReturn(10);
     *  when(mock2.get(0)).thenReturn(20);
     *
     *  //using mocks by calling stubbed get(0) methods:
     *  System.out.println(mock1.get(0)); //prints 10
     *  System.out.println(mock2.get(0)); //prints 20
     *
     *  //using mocks by calling clear() methods:
     *  mock1.clear();
     *  mock2.clear();
     *
     *  //verification:
     *  verify(mock1).clear();
     *  verify(mock2).clear();
     *
     *  //verifyNoMoreInteractions() fails because get() methods were not accounted for.
     *  try { verifyNoMoreInteractions(mock1, mock2); } catch (NoInteractionsWanted e);
     *
     *  //However, if we ignore stubbed methods then we can verifyNoMoreInteractions()
     *  verifyNoMoreInteractions(ignoreStubs(mock1, mock2));
     *
     *  //Remember that ignoreStubs() <b>*changes*</b> the input mocks and returns them for convenience.
     * </code></pre>
     * Ignoring stubs can be used with <b>verification in order</b>:
     * <pre class="code"><code class="java">
     *  List list = mock(List.class);
     *  when(mock.get(0)).thenReturn("foo");
     *
     *  list.add(0);
     *  System.out.println(list.get(0)); //we don't want to verify this
     *  list.clear();
     *
     *  InOrder inOrder = inOrder(ignoreStubs(list));
     *  inOrder.verify(list).add(0);
     *  inOrder.verify(list).clear();
     *  inOrder.verifyNoMoreInteractions();
     * </code></pre>
     *
     * @since 1.9.0
     * @param mocks input mocks that will be changed
     * @return the same mocks that were passed in as parameters
     */
    public static Object[] ignoreStubs(Object... mocks) {
        return MOCKITO_CORE.ignoreStubs(mocks);
    }

    /**
     * Allows verifying exact number of invocations. E.g:
     * <pre class="code"><code class="java">
     *   verify(mock, times(2)).someMethod("some arg");
     * </code></pre>
     *
     * See examples in javadoc for {@link Mockito} class
     *
     * @param wantedNumberOfInvocations wanted number of invocations
     *
     * @return verification mode
     */
    public static VerificationMode times(int wantedNumberOfInvocations) {
        return VerificationModeFactory.times(wantedNumberOfInvocations);
    }

    /**
     * Alias to <code>times(0)</code>, see {@link Mockito#times(int)}
     * <p>
     * Verifies that interaction did not happen. E.g:
     * <pre class="code"><code class="java">
     *   verify(mock, never()).someMethod();
     * </code></pre>
     *
     * <p>
     * If you want to verify there were NO interactions with the mock
     * check out {@link Mockito#verifyZeroInteractions(Object...)}
     * or {@link Mockito#verifyNoMoreInteractions(Object...)}
     * <p>
     * See examples in javadoc for {@link Mockito} class
     *
     * @return verification mode
     */
    public static VerificationMode never() {
        return times(0);
    }

    /**
     * Allows at-least-once verification. E.g:
     * <pre class="code"><code class="java">
     *   verify(mock, atLeastOnce()).someMethod("some arg");
     * </code></pre>
     * Alias to <code>atLeast(1)</code>.
     * <p>
     * See examples in javadoc for {@link Mockito} class
     *
     * @return verification mode
     */
    public static VerificationMode atLeastOnce() {
        return VerificationModeFactory.atLeastOnce();
    }

    /**
     * Allows at-least-x verification. E.g:
     * <pre class="code"><code class="java">
     *   verify(mock, atLeast(3)).someMethod("some arg");
     * </code></pre>
     *
     * See examples in javadoc for {@link Mockito} class
     *
     * @param minNumberOfInvocations minimum number of invocations
     *
     * @return verification mode
     */
    public static VerificationMode atLeast(int minNumberOfInvocations) {
        return VerificationModeFactory.atLeast(minNumberOfInvocations);
    }

    /**
     * Allows at-most-x verification. E.g:
     * <pre class="code"><code class="java">
     *   verify(mock, atMost(3)).someMethod("some arg");
     * </code></pre>
     *
     * See examples in javadoc for {@link Mockito} class
     *
     * @param maxNumberOfInvocations max number of invocations
     *
     * @return verification mode
     */
    public static VerificationMode atMost(int maxNumberOfInvocations) {
        return VerificationModeFactory.atMost(maxNumberOfInvocations);
    }

    /**
     * Allows non-greedy verification in order.  For example
     * <pre class="code"><code class="java">
     *   inOrder.verify( mock, calls( 2 )).someMethod( "some arg" );
     * </code></pre>
     * <ul>
     * <li>will not fail if the method is called 3 times, unlike times( 2 )</li>
     * <li>will not mark the third invocation as verified, unlike atLeast( 2 )</li>
     * </ul>
     * This verification mode can only be used with in order verification.
     * @param wantedNumberOfInvocations number of invocations to verify
     * @return  verification mode
     */
    public static VerificationMode calls( int wantedNumberOfInvocations ){
        return VerificationModeFactory.calls( wantedNumberOfInvocations );
    }

    /**
     * Allows checking if given method was the only one invoked. E.g:
     * <pre class="code"><code class="java">
     *   verify(mock, only()).someMethod();
     *   //above is a shorthand for following 2 lines of code:
     *   verify(mock).someMethod();
     *   verifyNoMoreInvocations(mock);
     * </code></pre>
     *
     * <p>
     * See also {@link Mockito#verifyNoMoreInteractions(Object...)}
     * <p>
     * See examples in javadoc for {@link Mockito} class
     *
     * @return verification mode
     */
    public static VerificationMode only() {
    	return VerificationModeFactory.only();
    }

    /**
     * Allows verifying with timeout. It causes a verify to wait for a specified period of time for a desired
     * interaction rather than fails immediately if had not already happened. May be useful for testing in concurrent
     * conditions.
     * <p>
     * It feels this feature should be used rarely - figure out a better way of testing your multi-threaded system
     * <p>
     * Not yet implemented to work with InOrder verification.
     * <pre class="code"><code class="java">
     *   //passes when someMethod() is called within given time span
     *   verify(mock, timeout(100)).someMethod();
     *   //above is an alias to:
     *   verify(mock, timeout(100).times(1)).someMethod();
     *
     *   //passes when someMethod() is called <b>*exactly*</b> 2 times within given time span
     *   verify(mock, timeout(100).times(2)).someMethod();
     *
     *   //passes when someMethod() is called <b>*at least*</b> 2 times within given time span
     *   verify(mock, timeout(100).atLeast(2)).someMethod();
     *
     *   //verifies someMethod() within given time span using given verification mode
     *   //useful only if you have your own custom verification modes.
     *   verify(mock, new Timeout(100, yourOwnVerificationMode)).someMethod();
     * </code></pre>
     *
     * See examples in javadoc for {@link Mockito} class
     *
     * @param millis - time span in millisecond
     *
     * @return verification mode
     */
    public static VerificationWithTimeout timeout(int millis) {
        return new Timeout(millis, VerificationModeFactory.times(1));
    }

    /**
     * First of all, in case of any trouble, I encourage you to read the Mockito FAQ: <a href="http://code.google.com/p/mockito/wiki/FAQ">http://code.google.com/p/mockito/wiki/FAQ</a>
     * <p>
     * In case of questions you may also post to mockito mailing list: <a href="http://groups.google.com/group/mockito">http://groups.google.com/group/mockito</a>
     * <p>
     * <code>validateMockitoUsage()</code> <b>explicitly validates</b> the framework state to detect invalid use of Mockito.
     * However, this feature is optional <b>because Mockito validates the usage all the time...</b> but there is a gotcha so read on.
     * <p>
     * Examples of incorrect use:
     * <pre class="code"><code class="java">
     * //Oups, someone forgot thenReturn() part:
     * when(mock.get());
     *
     * //Oups, someone put the verified method call inside verify() where it should be outside:
     * verify(mock.execute());
     *
     * //Oups, someone has used EasyMock for too long and forgot to specify the method to verify:
     * verify(mock);
     * </code></pre>
     *
     * Mockito throws exceptions if you misuse it so that you know if your tests are written correctly.
     * The gotcha is that Mockito does the validation <b>next time</b> you use the framework (e.g. next time you verify, stub, call mock etc.).
     * But even though the exception might be thrown in the next test,
     * the exception <b>message contains a navigable stack trace element</b> with location of the defect.
     * Hence you can click and find the place where Mockito was misused.
     * <p>
     * Sometimes though, you might want to validate the framework usage explicitly.
     * For example, one of the users wanted to put <code>validateMockitoUsage()</code> in his <code>&#064;After</code> method
     * so that he knows immediately when he misused Mockito.
     * Without it, he would have known about it not sooner than <b>next time</b> he used the framework.
     * One more benefit of having <code>validateMockitoUsage()</code> in <code>&#064;After</code> is that jUnit runner will always fail in the test method with defect
     * whereas ordinary 'next-time' validation might fail the <b>next</b> test method.
     * But even though JUnit might report next test as red, don't worry about it
     * and just click at navigable stack trace element in the exception message to instantly locate the place where you misused mockito.
     * <p>
     * <b>Built-in runner: {@link MockitoJUnitRunner}</b> does validateMockitoUsage() after each test method.
     * <p>
     * Bear in mind that <b>usually you don't have to <code>validateMockitoUsage()</code></b>
     * and framework validation triggered on next-time basis should be just enough,
     * mainly because of enhanced exception message with clickable location of defect.
     * However, I would recommend validateMockitoUsage() if you already have sufficient test infrastructure
     * (like your own runner or base class for all tests) because adding a special action to <code>&#064;After</code> has zero cost.
     * <p>
     * See examples in javadoc for {@link Mockito} class
     */
    public static void validateMockitoUsage() {
        MOCKITO_CORE.validateMockitoUsage();
    }

    /**
     * Allows mock creation with additional mock settings.
     * <p>
     * Don't use it too often.
     * Consider writing simple tests that use simple mocks.
     * Repeat after me: simple tests push simple, KISSy, readable & maintainable code.
     * If you cannot write a test in a simple way - refactor the code under test.
     * <p>
     * Examples of mock settings:
     * <pre class="code"><code class="java">
     *   //Creates mock with different default answer & name
     *   Foo mock = mock(Foo.class, withSettings()
     *       .defaultAnswer(RETURNS_SMART_NULLS)
     *       .name("cool mockie"));
     *
     *   //Creates mock with different default answer, descriptive name and extra interfaces
     *   Foo mock = mock(Foo.class, withSettings()
     *       .defaultAnswer(RETURNS_SMART_NULLS)
     *       .name("cool mockie")
     *       .extraInterfaces(Bar.class));
     * </code></pre>
     * {@link MockSettings} has been introduced for two reasons.
     * Firstly, to make it easy to add another mock settings when the demand comes.
     * Secondly, to enable combining different mock settings without introducing zillions of overloaded mock() methods.
     * <p>
     * See javadoc for {@link MockSettings} to learn about possible mock settings.
     * <p>
     *
     * @return mock settings instance with defaults.
     */
    public static MockSettings withSettings() {
        return new MockSettingsImpl().defaultAnswer(RETURNS_DEFAULTS);
    }

    /**
     * Helps debugging failing tests. Experimental - use at your own risk. We're not sure if this method will stay in public api.
     */
    @Deprecated
    static MockitoDebugger debug() {
        return new MockitoDebuggerImpl();
    }
}