anchor.diff:     */
     void type(Type id, {Type implementedBy, CreationStrategy creation,
         Visibility visibility}) {
  -    _providersCache = null;
  +    _dirty();
       _providers[id] = new _TypeProvider(
           implementedBy == null ? id : implementedBy, creation, visibility);
     }
  
positive.code:    */
    void value(Type id, value,
        {CreationStrategy creation, Visibility visibility}) {
      _providersCache = null;
      _providers[id] = new _ValueProvider(value, creation, visibility);
    }
  
  
negative.code:    * child (installed) modules.
     */
    Map<Type, _Provider> get _bindings {
      if (_isDirty) {
        _providersCache = <Type, _Provider>{};
        _childModules.forEach((child) => _providersCache.addAll(child._bindings));
        _providersCache.addAll(_providers);
  