/**
   * Returns the single element contained in {@code iterator}.
   *
   * @throws NoSuchElementException if the iterator is empty
   * @throws IllegalArgumentException if the iterator contains multiple elements. The state of the
   *     iterator is unspecified.
   */
  @ParametricNullness
  public static <T extends @Nullable Object> T getOnlyElement(Iterator<T> iterator) {
    T first = iterator.next();
    if (!iterator.hasNext()) {

        saveToken();
        return doMove(form, 0);
    }

    /**
     * Handles pagination movement logic.
     *
     * @param form the list form containing current state
     * @param move the direction to move (-1 for previous, 0 for specific page, 1 for next)
     * @return HTML response with moved page results
     */
    protected HtmlResponse doMove(final ListForm form, final int move) {

     * iterator's next element and pass it to the reference iterator through this method so it can
     * return the same element. This enables the assertion to pass and the reference iterator to
     * properly update its state.
     */
    void promoteToNext(E e) {
      if (nextElements.remove(e)) {
        nextElements.push(e);
      } else {
        throw new UnknownElementException(nextElements, e);
      }
    }

// doPing checks last ping time and sends another ping.
func (m *muxClient) doPing(respHandler chan<- Response) (ok bool) {
	m.respMu.Lock()
	if m.closed {
		m.respMu.Unlock()
		// Already closed. This is not an error state;
		// we may just be delivering the last responses.
		return true
	}

	// Only check ping when not closed.
	if got := time.Since(time.Unix(0, atomic.LoadInt64(&m.LastPong))); got > m.clientPingInterval*2 {

labels.destinationIndicator=Zielindikator
labels.user_internationaliSDNNumber=Internationale ISDN-Nummer
labels.internationaliSDNNumber=Internationale ISDN-Nummer
labels.user_state=Bundesland
labels.state=Bundesland
labels.user_employeeType=Mitarbeitertyp
labels.employeeType=Mitarbeitertyp
labels.user_facsimileTelephoneNumber=Faxnummer
labels.facsimileTelephoneNumber=Faxnummer
labels.user_postOfficeBox=Postfach

labels.destinationIndicator=Indikator Tujuan
labels.user_internationaliSDNNumber=Nomor ISDN Internasional
labels.internationaliSDNNumber=Nomor ISDN Internasional
labels.user_state=Provinsi
labels.state=Provinsi
labels.user_employeeType=Jenis Pegawai
labels.employeeType=Jenis Pegawai
labels.user_facsimileTelephoneNumber=Nomor Telepon Faksimile
labels.facsimileTelephoneNumber=Nomor Telepon Faksimile

labels.destinationIndicator=Informacje o adresie usługi telegramowej
labels.user_internationaliSDNNumber=Międzynarodowy numer ISDN
labels.internationaliSDNNumber=Międzynarodowy numer ISDN
labels.user_state=Stan/Prowincja
labels.state=Stan/Prowincja
labels.user_employeeType=Typ pracownika
labels.employeeType=Typ pracownika
labels.user_facsimileTelephoneNumber=Numer faksu
labels.facsimileTelephoneNumber=Numer faksu

labels.destinationIndicator=Hedef Göstergesi
labels.user_internationaliSDNNumber=Uluslararası ISDN Numarası
labels.internationaliSDNNumber=Uluslararası ISDN Numarası
labels.user_state=Eyalet
labels.state=Eyalet
labels.user_employeeType=Çalışan Türü
labels.employeeType=Çalışan Türü
labels.user_facsimileTelephoneNumber=Faks Telefon Numarası
labels.facsimileTelephoneNumber=Faks Telefon Numarası

     */
    protected void writeFesenJson(final ZipOutputStream zos, final String id) {
        writeElastisearchJsonApi(zos, id, "cluster", "health");
        writeElastisearchJsonApi(zos, id, "cluster", "state");
        writeElastisearchJsonApi(zos, id, "cluster", "stats");
        writeElastisearchJsonApi(zos, id, "cluster", "pending_tasks");
        writeElastisearchJsonApi(zos, id, "nodes", "stats");

      output_gradients, result, /*build_default_zeros_grads*/ false));
  return absl::OkStatus();
}

// Helper functions which delegate to `AbstractOperation`, update
// the state of the ForwardOperation and call the tape as appropriate.
// These APIs are mainly to facilitate testing and are subject to change.
namespace internal {
absl::Status Reset(AbstractOperation* op_, const char* op,