/**
  * Validate a user against the given credentials.
  *
  * @param  \Illuminate\Contracts\Auth\Authenticatable $user
  * @param  array                                      $credentials
  * @return bool
  */
 public function validateCredentials(Authenticatable $user, array $credentials)
 {
     return $this->ldapService->validateUserCredentials($user, $credentials['username'], $credentials['password']);
 }