001/*
002 * Copyright (C) 2013 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package com.google.common.collect.testing.google;
018
019import com.google.common.annotations.GwtCompatible;
020import com.google.common.collect.Multiset;
021import com.google.common.collect.testing.features.Feature;
022import com.google.common.collect.testing.features.TesterAnnotation;
023import java.lang.annotation.Inherited;
024import java.lang.annotation.Retention;
025import java.lang.annotation.RetentionPolicy;
026import java.util.Collections;
027import java.util.Set;
028
029/**
030 * Optional features of classes derived from {@link Multiset}.
031 *
032 * @author Louis Wasserman
033 */
034@SuppressWarnings("rawtypes") // maybe avoidable if we rework the whole package?
035@GwtCompatible
036public enum MultisetFeature implements Feature<Multiset> {
037  /**
038   * Indicates that elements from {@code Multiset.entrySet()} update to reflect changes in the
039   * backing multiset.
040   */
041  ENTRIES_ARE_VIEWS;
042
043  @Override
044  public Set<Feature<? super Multiset>> getImpliedFeatures() {
045    return Collections.emptySet();
046  }
047
048  @Retention(RetentionPolicy.RUNTIME)
049  @Inherited
050  @TesterAnnotation
051  public @interface Require {
052    public abstract MultisetFeature[] value() default {};
053
054    public abstract MultisetFeature[] absent() default {};
055  }
056}