addAction(intent, action, parameters, fn) {
    if (this.posAction(intent, action, parameters) === -1) {
      if (!this.actions[intent]) {
        this.actions[intent] = [];
      }
      this.actions[intent].push({ action, parameters });
      if (fn) {
        this.actionsMap[action] = fn;
      }
    }
  }
Add an action to a given intent.
@param {String} intent Name of the intent.
@param {String} action Action to be executed
@param {any[]} parameters Parameters of the action
@param {function} [fn] Function of the action