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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.collections4.iterators;
18  
19  import java.util.Iterator;
20  import java.util.Objects;
21  
22  /**
23   * Provides basic behavior for decorating an iterator with extra functionality without committing the generic type of the Iterator implementation.
24   * <p>
25   * All methods are forwarded to the decorated iterator.
26   * </p>
27   *
28   * @param <I> the type of the iterator being decorated.
29   * @param <O> the type of elements returned by this iterator.
30   * @since 4.0
31   */
32  public abstract class AbstractUntypedIteratorDecorator<I, O> implements Iterator<O> {
33  
34      /** The iterator being decorated */
35      private final Iterator<I> iterator;
36  
37      /**
38       * Create a new AbstractUntypedIteratorDecorator.
39       *
40       * @param iterator  the iterator to decorate
41       * @throws NullPointerException if the iterator is null
42       */
43      protected AbstractUntypedIteratorDecorator(final Iterator<I> iterator) {
44          this.iterator = Objects.requireNonNull(iterator, "iterator");
45      }
46  
47      /**
48       * Gets the iterator being decorated.
49       *
50       * @return the decorated iterator
51       */
52      protected Iterator<I> getIterator() {
53          return iterator;
54      }
55  
56      @Override
57      public boolean hasNext() {
58          return iterator.hasNext();
59      }
60  
61      @Override
62      public void remove() {
63          iterator.remove();
64      }
65  
66  }