private function checkKey($key)
 {
     $user = $this->userRepository->findUserByKey($key);
     if ($user) {
         return false;
     }
     return true;
 }
 /**
  * Checks if API-Key is valid
  * @param string $apiKey
  */
 private function isKeyValid($apiKey)
 {
     $user = $this->userRepository->findUserByKey($apiKey);
     if (!$user) {
         throw new AccessDeniedHttpException('Your API key is not valid');
     }
     return $user;
 }
 /**
  * @param InputInterface $input
  * @param OutputInterface $output
  */
 protected function execute(InputInterface $input, OutputInterface $output)
 {
     $table = new Table($output);
     $table->setHeaders(['ID', 'Username', 'API-Key'])->addRows($this->userRepository->findAll());
     $table->render();
 }