1package javax.annotation; 2 3import java.lang.annotation.Documented; 4import java.lang.annotation.Retention; 5import java.lang.annotation.RetentionPolicy; 6 7import javax.annotation.meta.TypeQualifierNickname; 8import javax.annotation.meta.When; 9 10/** Used to annotate a value of unknown sign */ 11 12@Documented 13@TypeQualifierNickname 14@Nonnegative(when = When.UNKNOWN) 15@Retention(RetentionPolicy.RUNTIME) 16public @interface Signed { 17 18} 19