anchor.diff:    Map<A, CommandBuilder<AbstractModel>> handlers;
   
     /**
  -   * A(ctionTypes) / CommandBuilders mapping injection
  +   * RequestTypes / CommandBuilders mapping injection
      */
     CommanderConfig(Map<A, CommandBuilder> map) {
       handlers = map;
  
positive.code:  * listen to dispatcher's stream of actions and map them to commands, executed on the store
   */
  class Commander {
    CommanderConfig config;
  
    Store<AbstractModel> store;
  
    Dispatcher dispatcher;
  
    Commander(CommanderConfig this.config, Store<AbstractModel> this.store,
        Dispatcher this.dispatcher) {
      dispatcher.onDispatch.listen((Request a) => handle(a));
    }
  
    cancel() => store.cancel();
  
    _exec(Command<AbstractModel> c) {
      store.update(c);
    }
  
    handle(Request a) {
      var handler = this.config.getHandler(a.actionType);
      try{
        _exec(handler(a.value));
      } catch (err){
        print('Commander.handle... No command defined for this Action ${a} \n $err');
      }
  
negative.code:     return handlers.keys.contains(type) ? handlers[type] : null;
    }
  
    /**
     * add post constructor
     */
     // TODO : define use cases
    void addHandler(Request a, CommandBuilder<AbstractModel> constructor) {
      handlers[a.actionType] = constructor;
    }
  