public Comparator<? super K> comparator() {
      synchronized (mutex) {
        return delegate().comparator();
      }
    }

    @Override
    public K firstKey() {
      synchronized (mutex) {
        return delegate().firstKey();
      }
    }

    @Override
    public SortedMap<K, V> headMap(K toKey) {
      synchronized (mutex) {

    public Comparator<? super K> comparator() {
      synchronized (mutex) {
        return delegate().comparator();
      }
    }

    @Override
    public K firstKey() {
      synchronized (mutex) {
        return delegate().firstKey();
      }
    }

    @Override
    public SortedMap<K, V> headMap(K toKey) {
      synchronized (mutex) {

      replica.put(newValue, new AtomicInteger(1));
    }
  }

  private static void removeMinFromReplica(
      SortedMap<Integer, AtomicInteger> replica, int minValue) {
    Integer replicatedMinValue = replica.firstKey();
    assertEquals(replicatedMinValue, (Integer) minValue);
    removeFromReplica(replica, replicatedMinValue);
  }

  private static void removeMaxFromReplica(

   */
  @Override
  public Comparator<? super K> comparator() {
    return keySet().comparator();
  }

  @Override
  public K firstKey() {
    return keySet().first();
  }

  @Override
  public K lastKey() {
    return keySet().last();
  }

  private ImmutableSortedMap<K, V> getSubMap(int fromIndex, int toIndex) {

   */
  @Override
  public Comparator<? super K> comparator() {
    return keySet().comparator();
  }

  @Override
  public K firstKey() {
    return keySet().first();
  }

  @Override
  public K lastKey() {
    return keySet().last();
  }

  private ImmutableSortedMap<K, V> getSubMap(int fromIndex, int toIndex) {

        if ( prefixLen > 1 ) {
            prefixLen--;
            int firstSep = this.canon.indexOf('/', 1);
            if ( firstSep < 0 ) {
                this.share = this.canon.substring(1);
                this.unc = "\\";
            }
            else if ( firstSep == prefixLen ) {
                this.share = this.canon.substring(1, firstSep);
                this.unc = "\\";
            }
            else {

            var firstDay = moment([year, month, 1]);
            var lastDay = moment([year, month, daysInMonth]);
            var lastMonth = moment(firstDay).subtract(1, 'month').month();
            var lastYear = moment(firstDay).subtract(1, 'month').year();
            var daysInLastMonth = moment([lastYear, lastMonth]).daysInMonth();
            var dayOfWeek = firstDay.day();

        URI dfsRoot = new URI(getDFSRootURL());
        String dfsRootPath = dfsRoot.getPath();
        int firstSep = dfsRootPath.indexOf('/', 1);
        String dfsShare;
        if ( firstSep > 0 ) {
            dfsShare = dfsRootPath.substring(1, firstSep);
        }
        else {
            dfsShare = dfsRootPath.substring(1, dfsRootPath.length() - 1);
        }
        return dfsShare;

			ext := tok.String()
			curArrangement, err := arch.ARM64RegisterArrangement(reg, name, ext)
			if err != nil {
				p.errorf("%v", err)
			}
			if firstReg == -1 {
				// only record the first register and arrangement
				firstReg = int(reg)
				nextReg = firstReg
				arrangement = curArrangement
			} else if curArrangement != arrangement {
				p.errorf("inconsistent arrangement in ARM64 register list")

            Set<String> listLinks = new HashSet<>(Arrays.asList(list));
            int firstSep = link.indexOf('/');
            if ( firstSep == link.length() - 1 ) {
                // single level
                assertTrue("Link not found " + link, listLinks.contains(link));
            }
            else {
                link = link.substring(0, firstSep + 1);
                // single level