anchor.diff:  
     StreamController<String> _controller;
     String _name;
  -  
  +
     /**
      * The next state's name.
      * 
      * **Important:** You can controll where you want to go with this member.
      */
     String nextState;
  -  
  +
     /**
      * Acces to the main game object.
      * */
  
positive.code:    * * _name: the state's name
     * * nextState: next state's name(optional)
     * */
    State(this._name, [String nextState = null]): nextState = nextState {
      _controller = new StreamController<String>(onListen: _onListen, onPause:
          _onPause, onResume: _onResume, onCancel: _onCancel);
    }
    
    /**
     * This methode can only be used by the [StateManager]'s object.
     * 
  
negative.code:   void endState() {
      _controller.add(_PAUSE);
    }
  
    /**
     * This kills that state, so you can not return back to this state
     * */
  