Remove insertRange.

sdk/lib/html/html_common/filtered_element_list.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.
 
 part of html_common;
 
 /**
  * An indexable collection of a node's descendants in the document tree,
  * filtered so that only elements are in the collection.
  */
@@ skipping 62 matching lines @@
 
   void setRange(int start, int end, Iterable<Element> iterable,
                 [int skipCount = 0]) {
     throw new UnimplementedError();
   }
 
   void removeRange(int start, int end) {
     _filtered.sublist(start, end).forEach((el) => el.remove());
   }
 
-  void insertRange(int start, int rangeLength, [initialValue = null]) {
-    throw new UnimplementedError();
-  }
-
   void clear() {
     // Currently, ElementList#clear clears even non-element nodes, so we follow
     // that behavior.
     _childNodes.clear();
   }
 
   Element removeLast() {
     final result = this.last;
     if (result != null) {
       result.remove();
@@ skipping 96 matching lines @@
   Element get single => _filtered.single;
 
   Element min([int compare(Element a, Element b)]) => _filtered.min(compare);
 
   Element max([int compare(Element a, Element b)]) => _filtered.max(compare);
 
   Map<int, Element> asMap() {
     return IterableMixinWorkaround.asMapList(this);
   }
 }