subtype.isSubtypeOf(this), "%s does not appear to be a subtype of %s", subtype, this);
    return subtype;
  }

  /**
   * Returns true if this type is a supertype of the given {@code type}. "Supertype" is defined
   * according to <a
   * href="http://docs.oracle.com/javase/specs/jls/se8/html/jls-4.html#jls-4.5.1">the rules for type
   * arguments</a> introduced with Java generics.
   *
   * @since 19.0
   */

  // Gets and Timed Gets
  //
  // * Be responsive to interruption
  // * Don't create Waiter nodes if you aren't going to park, this helps reduce contention on the
  //   waiters field.
  // * Future completion is defined by when #value becomes non-null/non SetFuture
  // * Future completion can be observed if the waiters field contains a TOMBSTONE

  // Timed Get
  // There are a few design constraints to consider

       * template to be null (though we do handle that case gracefully at runtime). I've left this
       * one as it is because one of our users has defined a wrapper API around Preconditions,
       * declaring a checkState method that accepts a possibly null template. So we'd need to update
       * that user first.
       */
      @CheckForNull String errorMessageTemplate,

    verifySortedSetContents(set, SOME_ITERABLE, null);
  }

  public void testNewTreeSetFromIterableDerived() {
    Iterable<Derived> iterable = Arrays.asList(new Derived("foo"), new Derived("bar"));
    TreeSet<Derived> set = Sets.newTreeSet(iterable);
    assertThat(set).containsExactly(new Derived("bar"), new Derived("foo")).inOrder();
  }

  public void testNewTreeSetFromIterableNonGeneric() {
    Iterable<LegacyComparable> iterable =

       * template to be null (though we do handle that case gracefully at runtime). I've left this
       * one as it is because one of our users has defined a wrapper API around Preconditions,
       * declaring a checkState method that accepts a possibly null template. So we'd need to update
       * that user first.
       */
      @CheckForNull String errorMessageTemplate,

    assertNull(map.comparator());
  }

  public void testTreeMapDerived() {
    TreeMap<Derived, Integer> map = Maps.newTreeMap();
    assertEquals(Collections.emptyMap(), map);
    map.put(new Derived("foo"), 1);
    map.put(new Derived("bar"), 2);
    assertThat(map.keySet()).containsExactly(new Derived("bar"), new Derived("foo")).inOrder();
    assertThat(map.values()).containsExactly(2, 1).inOrder();

    assertNull(map.comparator());
  }

  public void testTreeMapDerived() {
    TreeMap<Derived, Integer> map = Maps.newTreeMap();
    assertEquals(Collections.emptyMap(), map);
    map.put(new Derived("foo"), 1);
    map.put(new Derived("bar"), 2);
    assertThat(map.keySet()).containsExactly(new Derived("bar"), new Derived("foo")).inOrder();
    assertThat(map.values()).containsExactly(2, 1).inOrder();

 *
 * <p>This class should be used by other collection classes only.
 *
 * @author Mike Bostock
 * @author Jared Levy
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
/*
 * I have decided not to bother adding @ParametricNullness annotations in this class. Adding them is
 * a lot of busy work, and the annotation matters only when the APIs to be annotated are visible to

 * loading), and fewer <a
 * href="https://github.com/google/guava/issues?q=is%3Aopen+is%3Aissue+label%3Apackage%3Dcache+label%3Atype%3Ddefect">bugs</a>.
 *
 * <p>Caffeine defines its own interfaces (<a
 * href="https://www.javadoc.io/doc/com.github.ben-manes.caffeine/caffeine/latest/com.github.benmanes.caffeine/com/github/benmanes/caffeine/cache/Cache.html">{@code
 * Cache}</a>, <a

   *     fetchCounterFuture, FetchException.class, x -> immediateFuture(0), directExecutor());
   * }</pre>
   *
   * <p>The fallback can also choose to propagate the original exception when desired:
   *
   * <pre>{@code
   * ListenableFuture<Integer> fetchCounterFuture = ...;
   *
   * // Falling back to a zero counter only in case the exception was a
   * // TimeoutException.