code: public function fromEvent($param = null, $default = null)
      {
          if (null === $param) {
              return $this->event->getParams();
          }
          return $this->event->getParam($param, $default);
      }
docs: Return all event parameters or a single event parameter.
  
  @param string $param Parameter name to retrieve, or null to get all.
  @param mixed $efault Default value to use when the parameter is missing.
  @return mixed
  @throws RuntimeException