public interface Function<F extends @Nullable Object, T extends @Nullable Object>
{
  /**
   * Returns the result of applying this function to {@code input}. This method is <i>generally
   * expected</i>, but not absolutely required, to have the following properties:
   *
   * <ul>
   *   <li>Its execution does not cause any observable side effects.
   *   <li>The computation is <i>consistent with equals</i>; that is, {@link Objects#equal

            won't.

            I have one idea for a better approach, but it's painful, and I haven't tested it: We
            could postprocess Collect.gwt.xml to add <skip> lines for all the files that should be
            covered by testModule.gwt.xml. Maybe I'll try it someday.

            [*] https://code.google.com/p/google-web-toolkit/wiki/ResourceOracle#When_multiple_PathPrefix_es_have_the_same_path

 * implement {@code BiPredicate<T, T>} (as it does in the main Guava artifact), but we currently
 * target a lower API level. In the meantime, if you have support for method references you can use
 * an equivalence as a bi-predicate like this: {@code myEquivalence::equivalent}.
 *
 * @author Bob Lee
 * @author Ben Yu
 * @author Gregory Kick

   * number of elements and every element of {@code iterator1} is equal to the corresponding element
   * of {@code iterator2}.
   *
   * <p>Note that this will modify the supplied iterators, since they will have been advanced some
   * number of elements forward.
   */
  public static boolean elementsEqual(Iterator<?> iterator1, Iterator<?> iterator2) {
    while (iterator1.hasNext()) {
      if (!iterator2.hasNext()) {

  private final transient int size;

  /*
   * We have some considerable complexity in these create methods because of
   * Builder.buildKeepingLast(). The same Builder might be called with buildKeepingLast() and then
   * buildOrThrow(), or vice versa. So in particular, if we modify alternatingKeysAndValues to
   * eliminate duplicate keys (for buildKeepingLast()) then we have to ensure that a later call to

   */
  public static final String RTT = "RTT";

  /**
   * The HTTP <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Save-Data">{@code
   * Save-Data}</a> header field name.
   *
   * @since 31.0
   */
  public static final String SAVE_DATA = "Save-Data";

  /**
   * The HTTP <a
   * href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Viewport-Width">{@code

   *
   * <p>The recommended solution for finding the {@code minimum} of some values depends on the type
   * of your data and the number of elements you have. Read more in the Guava User Guide article on
   * <a href="https://github.com/google/guava/wiki/CollectionUtilitiesExplained#comparators">{@code
   * Comparators}</a>.
   *

   * bug</b> as described in the deprecation text.
   *
   * <p>The C++ equivalent is the MurmurHash3_x86_32 function (Murmur3A), which however does not
   * have the bug.
   *
   * @deprecated This implementation produces incorrect hash values from the {@link
   *     HashFunction#hashString} method if the string contains non-BMP characters. Use {@link

      checkArgument(lowerBounds.length <= 1, "Wildcard cannot have more than one lower bounds.");
      if (lowerBounds.length == 1) {
        return supertypeOf(newArrayType(lowerBounds[0]));
      } else {
        Type[] upperBounds = wildcard.getUpperBounds();
        checkArgument(upperBounds.length == 1, "Wildcard should have only one upper bound.");
        return subtypeOf(newArrayType(upperBounds[0]));
      }

          // Inline the Comparator implementation rather than transforming with a Function
          // to save code size.
          Arrays.sort(
              entryArray,
              0,
              size,
              (e1, e2) -> {
                // requireNonNull is safe because the first `size` elements have been filled in.
                requireNonNull(e1);
                requireNonNull(e2);