/*

 * 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.sequence;

/**

 * Command representing the keeping of one object present in both sequences.

 * <p>

 * When one object of the first sequence <code>equals</code> another objects in

 * the second sequence at the right place, the {@link EditScript edit script}

 * transforming the first sequence into the second sequence uses an instance of

 * this class to represent the keeping of this object. The objects embedded in

 * these type of commands always come from the first sequence.

 * </p>

 *

 * @see SequencesComparator

 * @see EditScript

 *

 * @since 4.0

 */

public class KeepCommand<T> extends EditCommand<T> {

    /**

     * Simple constructor. Creates a new instance of KeepCommand

     *

     * @param object  the object belonging to both sequences (the object is a

     *   reference to the instance in the first sequence which is known

     *   to be equal to an instance in the second sequence)

     */

    public KeepCommand(final T object) {

        super(object);

    }

    /**

     * Accept a visitor. When a <code>KeepCommand</code> accepts a visitor, it

     * calls its {@link CommandVisitor#visitKeepCommand visitKeepCommand} method.

     *

     * @param visitor  the visitor to be accepted

     */

    @Override

    public void accept(final CommandVisitor<T> visitor) {

        visitor.visitKeepCommand(getObject());

    }

}