*
   * <p><b>{@code Stream} equivalent:</b> {@code stream.filter(type::isInstance).map(type::cast)}.
   * This does perform a little more work than necessary, so another option is to insert an
   * unchecked cast at some later point:
   *
   * <pre>
   * {@code @SuppressWarnings("unchecked") // safe because of ::isInstance check
   * ImmutableList<NewType> result =

       * a valid value for V.
       */
      return uncheckedNull();
    } else {
      @SuppressWarnings("unchecked") // this is the only other option
      V asV = (V) obj;
      return asV;
    }
  }

  @Override
  public boolean isDone() {
    final Object localValue = value;
    return localValue != null & !(localValue instanceof SetFuture);

    `@Deprecated` APIs will remain (again, unless they are `@Beta`). We have no
    plans to start removing things again, but officially, we're leaving our
    options open in case of surprises (like, say, a serious security problem).

3.  Guava has one dependency that is needed for linkage at runtime:
    `com.google.guava:failureaccess:1.0.2`. It also has

   * than this method, and this method in turn generally performs better than copying the list and
   * calling {@link Collections#sort(List)}.
   */
  // TODO(kevinb): rerun benchmarks including new options
  @SuppressWarnings("nullness") // TODO: b/316358623 - Remove after checker fix.
  public <E extends T> List<E> sortedCopy(Iterable<E> elements) {
    @SuppressWarnings("unchecked") // does not escape, and contains only E's

   * <p>All other properties of the transformed map, such as iteration order, are left intact. For
   * example, the code:
   *
   * <pre>{@code
   * NavigableMap<String, Boolean> options = Maps.newTreeMap();
   * options.put("verbose", false);
   * options.put("sort", true);
   * EntryTransformer<String, Boolean, String> flagPrefixer =
   *     new EntryTransformer<String, Boolean, String>() {

   *
   * <p>When the new X-Download-Options header is present with the value {@code noopen}, the user is
   * prevented from opening a file download directly; instead, they must first save the file
   * locally.
   *
   * @since 24.1
   */
  public static final String X_DOWNLOAD_OPTIONS = "X-Download-Options";