--- old/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/arrays/UndefinedArrayFilter.java	2016-12-15 11:26:15.000000000 +0100
+++ new/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/arrays/UndefinedArrayFilter.java	2016-12-15 11:26:14.000000000 +0100
@@ -77,9 +77,10 @@
     }
 
     @Override
-    public void shiftLeft(final int by) {
+    public ArrayData shiftLeft(final int by) {
         super.shiftLeft(by);
         undefined.shiftLeft(by, length());
+        return this;
     }
 
     @Override