/**
  * @param string $value
  *
  * @return bool
  */
 protected function query($value)
 {
     $class = $this->entityOptions->getUser();
     /** @var \PServerCore\Entity\UserInterface $user */
     $user = new $class();
     $user->setUsername($value);
     return $this->gameBackendService->isUserNameExists($user);
 }