* href="https://url.spec.whatwg.org/#percent-encode">uppercase</a> hexadecimal sequences.
   */
  public static Escaper urlFragmentEscaper() {
    return URL_FRAGMENT_ESCAPER;
  }

  private static final Escaper URL_FRAGMENT_ESCAPER =
      new PercentEscaper(URL_PATH_OTHER_SAFE_CHARS_LACKING_PLUS + "+/?", false);

all think me at home!  Why, I wouldn't say anything about it,
even if I fell off the top of the house!' (Which was very likely
true.)

  Down, down, down.  Would the fall NEVER come to an end!  `I
wonder how many miles I've fallen by this time?' she said aloud.
`I must be getting somewhere near the centre of the earth.  Let
me see:  that would be four thousand miles down, I think--' (for,
you see, Alice had learnt several things of this sort in her

 * SettableFuture} or one of the methods in the {@link Futures#immediateFuture Futures.immediate*}
 * family. <b>Avoid</b> creating a mock or stub {@code Future}. Mock and stub implementations are
 * fragile because they assume that only certain methods will be called and because they often
 * implement subtleties of the API improperly.
 *

   * accessed directly after this method returns. These conditions are ensured if the map is created
   * empty, passed directly to this method, and no reference to the map is retained, as illustrated
   * in the following code fragment:
   *
   * <pre>{@code
   * Set<Object> identityHashSet = Sets.newSetFromMap(
   *     new IdentityHashMap<Object, Boolean>());
   * }</pre>
   *
   * <p>The returned set is serializable if the backing map is.

 * SettableFuture} or one of the methods in the {@link Futures#immediateFuture Futures.immediate*}
 * family. <b>Avoid</b> creating a mock or stub {@code Future}. Mock and stub implementations are
 * fragile because they assume that only certain methods will be called and because they often
 * implement subtleties of the API improperly.
 *

all think me at home!  Why, I wouldn't say anything about it,
even if I fell off the top of the house!' (Which was very likely
true.)

  Down, down, down.  Would the fall NEVER come to an end!  `I
wonder how many miles I've fallen by this time?' she said aloud.
`I must be getting somewhere near the centre of the earth.  Let
me see:  that would be four thousand miles down, I think--' (for,
you see, Alice had learnt several things of this sort in her