--- jsr166/src/main/java/util/ArrayDeque.java	2017/10/22 17:44:02	1.132
+++ jsr166/src/main/java/util/ArrayDeque.java	2018/02/24 22:04:18	1.133
@@ -209,7 +209,7 @@ public class ArrayDeque<E> extends Abstr
      */
     public ArrayDeque(Collection<? extends E> c) {
         this(c.size());
-        addAll(c);
+        copyElements(c);
     }
 
     /**
@@ -325,11 +325,15 @@ public class ArrayDeque<E> extends Abstr
         final int s, needed;
         if ((needed = (s = size()) + c.size() + 1 - elements.length) > 0)
             grow(needed);
-        c.forEach(this::addLast);
+        copyElements(c);
         // checkInvariants();
         return size() > s;
     }
 
+    private void copyElements(Collection<? extends E> c) {
+        c.forEach(this::addLast);
+    }
+
     /**
      * Inserts the specified element at the front of this deque.
      *