* version.
   *
   * @throws UnsupportedOperationException always
   * @deprecated <b>Pass a key of type {@code Comparable} to use {@link
   *     ImmutableSortedMap#of(Comparable, Object)}.</b>
   */
  @DoNotCall("Pass a key of type Comparable")
  @Deprecated
  public static <K, V> ImmutableSortedMap<K, V> of(K k1, V v1) {
    throw new UnsupportedOperationException();

   * dummy version.
   *
   * @throws UnsupportedOperationException always
   * @deprecated <b>Pass a parameter of type {@code Comparable} to use {@link
   *     ImmutableSortedSet#of(Comparable)}.</b>
   */
  @DoNotCall("Pass a parameter of type Comparable")
  @Deprecated
  public static <E> ImmutableSortedSet<E> of(E element) {
    throw new UnsupportedOperationException();
  }

  // - @PolyNull means "@Nullable or @Nonnull"
  //   (That would be unsound for an input Iterable<@Nullable Foo>. So, if we wanted to use
  //   @PolyNull, we would have to restrict this method to non-null <T>. But it has users who pass
  //   iterables with null elements.)
  //
  // - @JointlyNullable means "@Nullable or no annotation"
  @CheckForNull
  public static <T extends @Nullable Object> T find(
      Iterable<? extends T> iterable,

   * take a principled stand on this, but the amount of such code is simply overwhelming. To avoid
   * creating a lot of compile errors that users would not find to be informative, we're giving in
   * and allowing callers to pass arguments that a nullness checker believes could be null.
   *
   * We still encourage people to use requireNonNull over checkNotNull for non-precondition checks.
   */

  /**

  @CheckForNull
  public final V getOrDefault(@CheckForNull Object key, @CheckForNull V defaultValue) {
    /*
     * Even though it's weird to pass a defaultValue that is null, some callers do so. Those who
     * pass a literal "null" should probably just use `get`, but I would expect other callers to
     * pass an expression that *might* be null. This could happen with:
     *
     * - a `getFooOrDefault(@CheckForNull Foo defaultValue)` method that returns

          // We unwind setFuture specifically to avoid StackOverflowErrors in the case of long
          // chains of SetFutures
          // Handling this special case is important because there is no way to pass an executor to
          // setFuture, so a user couldn't break the chain by doing this themselves.  It is also
          // potentially common if someone writes a recursive Futures.transformAsync transformer.

   *
   * <p><b>Note:</b> The returned view performs slightly better when {@code set1} is the smaller of
   * the two sets. If you have reason to believe one of your sets will generally be smaller than the
   * other, pass it first. Unfortunately, since this method sets the generic type of the returned
   * set based on the type of the first set passed, this could in rare cases force you to make a
   * cast, for example:
   *
   * <pre>{@code

 *
 * <p>The common ways to get an instance of {@code Ordering} are:
 *
 * <ul>
 *   <li>Subclass it and implement {@link #compare} instead of implementing {@link Comparator}
 *       directly
 *   <li>Pass a <i>pre-existing</i> {@link Comparator} instance to {@link #from(Comparator)}
 *   <li>Use the natural ordering, {@link Ordering#natural}
 * </ul>
 *
 * <h4>Chaining</h4>
 *

    list.add("a");
    list.add("b");
    Iterator<String> iterator = list.iterator();
    try {
      get(iterator, -1, "c");
      fail();
    } catch (IndexOutOfBoundsException expected) {
      // pass
    }
    assertTrue(iterator.hasNext());
  }

  public void testAdvance_basic() {
    List<String> list = newArrayList();
    list.add("a");
    list.add("b");

      }
    }
    Arrays.fill(elements, uniques, n, null);
    if (uniques == 1) {
      // There is only one element or elements are all duplicates
      @SuppressWarnings("unchecked") // we are careful to only pass in E
      // requireNonNull is safe because the first `uniques` elements are non-null.
      E element = (E) requireNonNull(elements[0]);
      return new SingletonImmutableSet<E>(element);