*/
  private static final Comparator<?> NATURAL_ORDER = Ordering.natural();

  private static final ImmutableSortedMap<Comparable<?>, Object> NATURAL_EMPTY_MAP =
      new ImmutableSortedMap<>(ImmutableSortedSet.emptySet(Ordering.natural()), ImmutableList.of());

  static <K, V> ImmutableSortedMap<K, V> emptyMap(Comparator<? super K> comparator) {
    if (Ordering.natural().equals(comparator)) {
      return of();
    } else {

      if (forwardComparator == null) {
        return (Comparator) Ordering.natural().reverse();
      } else {
        return reverse(forwardComparator);
      }
    }

    // If we inline this, we get a javac error.
    private static <T extends @Nullable Object> Ordering<T> reverse(Comparator<T> forward) {
      return Ordering.from(forward).reverse();
    }

    @Override

     *
     * @param <E> the element type of {@link PriorityBlockingQueue}
     * @param initialCapacity the initial capacity of the priority queue
     * @param comparator the comparator for ordering the elements in the priority queue
     * @return a new instance of {@link PriorityBlockingQueue}
     * @see PriorityBlockingQueue#PriorityBlockingQueue(int, Comparator)
     */

   * across different segments.
   *
   * The page replacement algorithm's data structures are kept casually consistent with the map. The
   * ordering of writes to a segment is sequentially consistent. An update to the map and recording
   * of reads may not be immediately reflected on the algorithm's data structures. These structures

    // These results are all incorrect, but there's no way (short of iterating over the result)
    // to verify that with an arbitrary ordering or comparator.
    assertEquals(ImmutableSortedMap.of(2, 0, 4, 0), Maps.subMap(map, Range.atLeast(4)));
    assertEquals(ImmutableSortedMap.of(8, 0, 10, 0), Maps.subMap(map, Range.atMost(8)));
    assertEquals(

        CommonServerMessageBlock smb = (CommonServerMessageBlock) request;
        final byte[] buffer = this.getContext().getBufferCache().getBuffer();
        try {
            // synchronize around encode and write so that the ordering for SMB1 signing can be maintained
            synchronized (this.outLock) {
                final int n = smb.encode(buffer, 4);
                Encdec.enc_uint32be(n & 0xFFFF, buffer, 0); /* 4 byte session message header */

   * computation is {@linkplain java.util.concurrent.Future#isDone() complete} or, if the
   * computation is already complete, immediately.
   *
   * <p>The callback is run on {@code executor}. There is no guaranteed ordering of execution of
   * callbacks, but any callback added through this method is guaranteed to be called once the
   * computation is complete.
   *

    // These results are all incorrect, but there's no way (short of iterating over the result)
    // to verify that with an arbitrary ordering or comparator.
    assertEquals(ImmutableSortedMap.of(2, 0, 4, 0), Maps.subMap(map, Range.atLeast(4)));
    assertEquals(ImmutableSortedMap.of(8, 0, 10, 0), Maps.subMap(map, Range.atMost(8)));
    assertEquals(