/*

  * 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.collections;

 import java.util.Collection;

 /**

  * Defines a collection that allows objects to be removed in some well-defined order.

  * <p>

  * The removal order can be based on insertion order (eg, a FIFO queue or a

  * LIFO stack), on access order (eg, an LRU cache), on some arbitrary comparator

  * (eg, a priority queue) or on any other well-defined ordering.

  * <p>

  * Note that the removal order is not necessarily the same as the iteration

  * order.  A <code>Buffer</code> implementation may have equivalent removal

  * and iteration orders, but this is not required.

  * <p>

  * This interface does not specify any behavior for 

  * {@link Object#equals(Object)} and {@link Object#hashCode} methods.  It

  * is therefore possible for a <code>Buffer</code> implementation to also

  * also implement {@link java.util.List}, {@link java.util.Set} or 

  * {@link Bag}.

  * <p>

  * <strong>Note:</strong> this class should be bytecode-identical to the 

  * version in commons collections. This is required to allow backwards 

  * compability with both previous versions of BeanUtils and also allow 

  * coexistance with both collections 2.1 and 3.0.

  *

  * @since Commons Collections 2.1

  * @version $Revision: 555824 $ $Date: 2007-07-12 20:27:15 -0400 (Thu, 12 Jul 2007) $

  * 

  * @author Avalon

  * @author Berin Loritsch

  * @author Paul Jack

  * @author Stephen Colebourne

  */

 public interface Buffer extends Collection {

     /**

      * Gets and removes the next object from the buffer.

      *

      * @return the next object in the buffer, which is also removed

      * @throws BufferUnderflowException if the buffer is already empty

      */

     Object remove();

     /**

      * Gets the next object from the buffer without removing it.

      *

      * @return the next object in the buffer, which is not removed

      * @throws BufferUnderflowException if the buffer is empty

      */

     Object get();

 }