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	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You 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 org.apache.commons.collections4.set;

	import java.util.Set;

	import org.apache.commons.collections4.Transformer;
	import org.apache.commons.collections4.collection.TransformedCollection;

	/**
	* Decorates another <code>Set</code> to transform objects that are added.
	* <p>
	* The add methods are affected by this class.
	* Thus objects must be removed or searched for using their transformed form.
	* For example, if the transformation converts Strings to Integers, you must
	* use the Integer form to remove objects.
	* </p>
	* <p>
	* This class is Serializable from Commons Collections 3.1.
	* </p>
	*
	* @param <E> the type of the elements in this set
	* @since 3.0
	*/
	public class TransformedSet<E> extends TransformedCollection<E> implements Set<E> {

	/** Serialization version */
	private static final long serialVersionUID = 306127383500410386L;

	/**
	* Factory method to create a transforming set.
	* <p>
	* If there are any elements already in the set being decorated, they
	* are NOT transformed.
	* Contrast this with {@link #transformedSet(Set, Transformer)}.
	*
	* @param <E> the element type
	* @param set the set to decorate, must not be null
	* @param transformer the transformer to use for conversion, must not be null
	* @return a new transformed set
	* @throws NullPointerException if set or transformer is null
	* @since 4.0
	*/
	public static <E> TransformedSet<E> transformingSet(final Set<E> set,
	final Transformer<? super E, ? extends E> transformer) {
	return new TransformedSet<>(set, transformer);
	}

	/**
	* Factory method to create a transforming set that will transform
	* existing contents of the specified set.
	* <p>
	* If there are any elements already in the set being decorated, they
	* will be transformed by this method.
	* Contrast this with {@link #transformingSet(Set, Transformer)}.
	*
	* @param <E> the element type
	* @param set the set to decorate, must not be null
	* @param transformer the transformer to use for conversion, must not be null
	* @return a new transformed set
	* @throws NullPointerException if set or transformer is null
	* @since 4.0
	*/
	public static <E> Set<E> transformedSet(final Set<E> set, final Transformer<? super E, ? extends E> transformer) {
	final TransformedSet<E> decorated = new TransformedSet<>(set, transformer);
	if (set.size() > 0) {
	@SuppressWarnings("unchecked") // set is type E
	final E[] values = (E[]) set.toArray(); // NOPMD - false positive for generics
	set.clear();
	for (final E value : values) {
	decorated.decorated().add(transformer.transform(value));
	}
	}
	return decorated;
	}

	//-----------------------------------------------------------------------
	/**
	* Constructor that wraps (not copies).
	* <p>
	* If there are any elements already in the set being decorated, they
	* are NOT transformed.
	*
	* @param set the set to decorate, must not be null
	* @param transformer the transformer to use for conversion, must not be null
	* @throws NullPointerException if set or transformer is null
	*/
	protected TransformedSet(final Set<E> set, final Transformer<? super E, ? extends E> transformer) {
	super(set, transformer);
	}

	@Override
	public boolean equals(final Object object) {
	return object == this \|\| decorated().equals(object);
	}

	@Override
	public int hashCode() {
	return decorated().hashCode();
	}

	}

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