1/*
2 * Copyright (C) 2013 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.collect.testing.google;
18
19import com.google.common.annotations.GwtCompatible;
20import com.google.common.collect.Multiset;
21import com.google.common.collect.testing.features.Feature;
22import com.google.common.collect.testing.features.TesterAnnotation;
23
24import java.lang.annotation.Inherited;
25import java.lang.annotation.Retention;
26import java.lang.annotation.RetentionPolicy;
27import java.util.Collections;
28import java.util.Set;
29
30/**
31 * Optional features of classes derived from {@link Multiset}.
32 *
33 * @author Louis Wasserman
34 */
35@GwtCompatible
36public enum MultisetFeature implements Feature<Multiset> {
37  /**
38   * Indicates that elements from {@code Multiset.entrySet()} update to reflect changes in the
39   * backing multiset.
40   */
41  ENTRIES_ARE_VIEWS;
42
43  @Override
44  public Set<Feature<? super Multiset>> getImpliedFeatures() {
45    return Collections.emptySet();
46  }
47
48  @Retention(RetentionPolicy.RUNTIME)
49  @Inherited
50  @TesterAnnotation
51  public @interface Require {
52    public abstract MultisetFeature[] value() default {};
53    public abstract MultisetFeature[] absent() default {};
54  }
55}
56