    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      https://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.collections4.multiset;
    018
    019import java.util.Comparator;
    020
    021import org.apache.commons.collections4.SortedMultiSet;
    022
    023/**
    024 * Decorates another {@code SortedMultiSet} to provide additional behavior.
    025 * <p>
    026 * Methods are forwarded directly to the decorated multiset.
    027 * </p>
    028 *
    029 * @param <E> The type held in the multiset
    030 * @since 4.6.0
    031 */
    032public abstract class AbstractSortedMultiSetDecorator<E>
    033        extends AbstractMultiSetDecorator<E> implements SortedMultiSet<E> {
    034
    035    /** Serialization version */
    036    private static final long serialVersionUID = 20260705L;
    037
    038    /**
    039     * Constructor only used in deserialization, do not use otherwise.
    040     */
    041    protected AbstractSortedMultiSetDecorator() {
    042    }
    043
    044    /**
    045     * Constructor that wraps (not copies).
    046     *
    047     * @param multiset  The multiset to decorate, must not be null
    048     * @throws NullPointerException if multiset is null
    049     */
    050    protected AbstractSortedMultiSetDecorator(final SortedMultiSet<E> multiset) {
    051        super(multiset);
    052    }
    053
    054    @Override
    055    public Comparator<? super E> comparator() {
    056        return decorated().comparator();
    057    }
    058
    059    /**
    060     * Gets the multiset being decorated.
    061     *
    062     * @return The decorated multiset
    063     */
    064    @Override
    065    protected SortedMultiSet<E> decorated() {
    066        return (SortedMultiSet<E>) super.decorated();
    067    }
    068
    069    @Override
    070    public E first() {
    071        return decorated().first();
    072    }
    073
    074    @Override
    075    public E last() {
    076        return decorated().last();
    077    }
    078
    079}