--- jsr166/src/main/java/util/Deque.java	2017/05/13 19:51:48	1.38
+++ jsr166/src/main/java/util/Deque.java	2017/05/31 19:02:33	1.39
@@ -448,6 +448,31 @@ public interface Deque<E> extends Queue<
      */
     E peek();
 
+    /**
+     * Adds all of the elements in the specified collection at the end
+     * of this deque, as if by calling {@link #addLast} on each one,
+     * in the order that they are returned by the collection's iterator.
+     *
+     * <p>When using a capacity-restricted deque, it is generally preferable
+     * to call {@link #offer(Object) offer} separately on each element.
+     *
+     * <p>An exception encountered while trying to add an element may result
+     * in only some of the elements having been successfully added when
+     * the associated exception is thrown.
+     *
+     * @param c the elements to be inserted into this deque
+     * @return {@code true} if this deque changed as a result of the call
+     * @throws IllegalStateException if not all the elements can be added at
+     *         this time due to insertion restrictions
+     * @throws ClassCastException if the class of an element of the specified
+     *         collection prevents it from being added to this deque
+     * @throws NullPointerException if the specified collection contains a
+     *         null element and this deque does not permit null elements,
+     *         or if the specified collection is null
+     * @throws IllegalArgumentException if some property of an element of the
+     *         specified collection prevents it from being added to this deque
+     */
+    boolean addAll(Collection<? extends E> c);
 
     // *** Stack methods ***