/**
  * Callback when a client suffers an error
  *
  * @param \WebSocketServer\Event\Event   $event   The event
  * @param \WebSocketServer\Socket\Client $client  The client
  * @param string                         $message The error description
  */
 public function onError(Event $event, Client $client, $message)
 {
     if ($user = $client->getAppData('user')) {
         $userId = $user->getId();
     } else {
         $userId = '#' . $client->getId();
     }
     $client->getServer()->sendToAllButClient($userId . ' fell over', $client);
 }