Implement getRange (returning an Iterable).

tools/dom/templates/html/impl/impl_Node.darttemplate

 // Copyright (c) 2012, 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.
 
 part of $LIBRARYNAME;
 
 /**
  * Lazy implementation of the child nodes of an element that does not request
  * the actual child nodes of an element until strictly necessary greatly
  * improving performance for the typical cases where it is not required.
@@ skipping 159 matching lines @@
         "Cannot setRange on immutable List.");
   }
   void removeRange(int start, int rangeLength) {
     throw new UnsupportedError(
         "Cannot removeRange on immutable List.");
   }
   void insertRange(int start, int rangeLength, [Node initialValue]) {
     throw new UnsupportedError(
         "Cannot insertRange on immutable List.");
   }
+
+  Iterable<Node> getRange(int start, int end) {
+    throw new UnimplementedError("NodeList.getRange");
+  }
+
   List<Node> sublist(int start, [int end]) {
     if (end == null) end == length;
     return Lists.getRange(this, start, end, <Node>[]);
   }
 
-  List<Node> getRange(int start, int rangeLength) =>
-      sublist(start, start + rangeLength);
-
   String toString() {
     StringBuffer buffer = new StringBuffer('[');
     buffer.writeAll(this, ', ');
     buffer.write(']');
     return buffer.toString();
   }
   // -- end List<Node> mixins.
 
   // TODO(jacobr): benchmark whether this is more efficient or whether caching
   // a local copy of $dom_childNodes is more efficient.
@@ skipping 158 matching lines @@
   }
 
   /**
    * Print out a String representation of this Node.
    */
   String toString() => localName == null ?
       (nodeValue == null ? super.toString() : nodeValue) : localName;
 
 $!MEMBERS
 }