fix packages for latest SDK changes

pkg/mdv/lib/src/template.dart

 // Copyright (c) 2013, 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 mdv;
 
 /** Extensions to [Element]s that behave as templates. */
 class _TemplateExtension extends _ElementExtension {
   var _model;
   BindingDelegate _bindingDelegate;
@@ skipping 23 matching lines @@
   /**
    * Creates an instance of the template.
    */
   DocumentFragment createInstance(model, BindingDelegate delegate) {
     var template = node.ref;
     if (template == null) template = node;
 
     var instance = _createDeepCloneAndDecorateTemplates(
         template.ref.content, delegate);
 
-    if (_instanceCreated != null) _instanceCreated.add(instance);
+    if (_instanceCreated != null) {
+      for (var callback in _instanceCreated) callback(instance);
+    }
 
     _addBindings(instance, model, delegate);
     _addTemplateInstanceRecord(instance, model);
     return instance;
   }
 
   /**
    * The data model which is inherited through the tree.
    */
   get model => _model;
@@ skipping 38 matching lines @@
   void _observePath() {}
   void boundValueChanged(newValue) {}
 
   void close() {
     if (closed) return;
     var templateIterator = _mdv(node)._templateIterator;
     if (templateIterator != null) templateIterator.inputs.unbind(property);
     super.close();
   }
 }