/**
  * {@inheritDoc}
  */
 public function listTubeUsed($askServer = false)
 {
     if ($this->dispatcher) {
         $this->dispatcher->dispatch(CommandEvent::LIST_TUBE_USED, new CommandEvent($this, ['askServer' => $askServer]));
     }
     return $this->pheanstalk->listTubeUsed($askServer);
 }