code: public function respond($step, $method, $args)
      {
          $method = strtolower($method);
          if (isset($this->at[$method][$step])) {
              if ($this->at[$method][$step]->isMatch($args)) {
                  $action = $this->at[$method][$step]->findFirstAction($args);
                  if (isset($action)) {
                      return $action->act();
                  }
              }
          }
          if (isset($this->always[$method])) {
              $action = $this->always[$method]->findFirstAction($args);
              if (isset($action)) {
                  return $action->act();
              }
          }
  
          return;
      }
docs: Actually carry out the action stored previously, if the parameters match.
  
  @param int $step          Time of call.
  @param string $method     Method name.
  @param array $args        The parameters making up the rest of the call.
  
  @return mixed             The result of the action.