anchor.diff:     */
     void factory(Type id, FactoryFn factoryFn,
         {CreationStrategy creation, Visibility visibility}) {
  -    _providersCache = null;
  +    _dirty();
       _providers[id] = new _FactoryProvider(factoryFn, creation, visibility);
     }
   
  
positive.code:    */
    void install(Module module) {
      _childModules.add(module);
      _providersCache = null;
    }
  }
  
  /** Deafault creation strategy is to instantiate on the defining injector. */
  
negative.code:    */
    void type(Type id, {Type implementedBy, CreationStrategy creation,
        Visibility visibility}) {
      _dirty();
      _providers[id] = new _TypeProvider(
          implementedBy == null ? id : implementedBy, creation, visibility);
    }
  