public function uploadAccount($hashAlgorithm, $hashKey, $accounts,
      $rounds, $memoryCost) {
    $data = array(
      'hashAlgorithm' => $hashAlgorithm,
      'signerKey' => Google_Utils::urlSafeB64Encode($hashKey),
      'users' => $accounts
    );
    if ($rounds) {
      $data['rounds'] = $rounds;
    }
    if ($memoryCost) {
      $data['memoryCost'] = $memoryCost;
    }
    $this->invokeGitkitApiWithServiceAccount('uploadAccount', $data);
  }