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/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.concurrent.ConcurrentMap;
import javax.annotation.CheckForNull;
/**
* A concurrent map which forwards all its method calls to another concurrent map. Subclasses should
* override one or more methods to modify the behavior of the backing map as desired per the decorator pattern.
*
* {@code default} method warning: This class forwards calls to only some {@code
* default} methods. Specifically, it forwards calls only for methods that existed before
* {@code default} methods were introduced. For newer methods, like {@code forEach}, it inherits
* their default implementations. When those implementations invoke methods, they invoke methods on
* the {@code ForwardingConcurrentMap}.
*
* @author Charles Fry
* @since 2.0
*/
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class ForwardingConcurrentMap extends ForwardingMap
implements ConcurrentMap {
/** Constructor for use by subclasses. */
protected ForwardingConcurrentMap() {}
@Override
protected abstract ConcurrentMap delegate();
@CanIgnoreReturnValue
@Override
@CheckForNull
public V putIfAbsent(K key, V value) {
return delegate().putIfAbsent(key, value);
}
@CanIgnoreReturnValue
@Override
public boolean remove(@CheckForNull Object key, @CheckForNull Object value) {
return delegate().remove(key, value);
}
@CanIgnoreReturnValue
@Override
@CheckForNull
public V replace(K key, V value) {
return delegate().replace(key, value);
}
@CanIgnoreReturnValue
@Override
public boolean replace(K key, V oldValue, V newValue) {
return delegate().replace(key, oldValue, newValue);
}
}