Make first and last getters.

lib/core/queue.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * A [Queue] is a collection that can be manipulated at both ends. One
  * can iterate over the elements of a queue through [forEach] or with
  * an [Iterator].
  */
 abstract class Queue<E> extends Collection<E> {
@@ skipping 39 matching lines @@
   /**
    * Adds all elements of [collection] at the end of the queue. The
    * length of the queue is extended by the length of [collection].
    */
   void addAll(Collection<E> collection);
 
   /**
    * Returns the first element of the queue. Throws an
    * [EmptyQueueException] exception if this queue is empty.
    */
-  E first();
+  E get first;
 
   /**
    * Returns the last element of the queue. Throws an
    * [EmptyQueueException] exception if this queue is empty.
    */
-  E last();
+  E get last;
 
   /**
    * Removes all elements in the queue. The size of the queue becomes zero.
    */
   void clear();
 }