code: protected function validateCredentials($credentials)
      {
          $credentials = array_filter($credentials);
  
          $keys = array_keys($credentials);
  
          $diff = array_diff($this->requiredCredentials, $keys);
  
          if (!empty($diff)) {
              throw new MissingCredentialsException('Missing Credentials: ' . implode($diff, ', '));
          }
  
          unset($credentials, $keys, $diff);
      }
docs: Validate Credentials Array
  
  @param $credentials
  @throws MissingCredentialsException