abstract class CollectionFuture<V extends @Nullable Object, C extends @Nullable Object>
    extends AggregateFuture<V, C> {
  /*
   * We access this field racily but safely. For discussion of a similar situation, see the comments
   * on the fields of TimeoutFuture. This field is slightly different from the fields discussed
   * there: cancel() never reads this field, only writes to it. That makes the race here completely

down a large rabbit-hole under the hedge.

  In another moment down went Alice after it, never once
considering how in the world she was to get out again.

  The rabbit-hole went straight on like a tunnel for some way,
and then dipped suddenly down, so suddenly that Alice had not a
moment to think about stopping herself before she found herself
falling down a very deep well.

      if (supportsRemove) {
        int initialSize = map.size();
        map.get(keyToRemove);
        map.remove(keyToRemove);
        // This line doesn't hold - see the Javadoc comments above.
        // assertEquals(expectedValue, oldValue);
        assertFalse(map.containsKey(keyToRemove));
        assertEquals(initialSize - 1, map.size());
      } else {
        try {

 * Condition.signal}).
 *
 * <p>A thread is said to <i>occupy</i> a monitor if it has <i>entered</i> the monitor but not yet
 * <i>left</i>. Only one thread may occupy a given monitor at any moment. A monitor is also
 * reentrant, so a thread may enter a monitor any number of times, and then must leave the same
 * number of times. The <i>enter</i> and <i>leave</i> operations have the same synchronization

     *     might be the keys' natural order)
     * @since 31.0
     */
    @Override
    @SuppressWarnings("unchecked") // see inline comments
    public ImmutableSortedMap<K, V> buildOrThrow() {
      switch (size) {
        case 0:
          return emptyMap(comparator);
        case 1:
          // We're careful to put only K and V instances in.

   * roughly) 2.5s longer. (2.5s is also the maximum length of time we will wait for a timed get
   * that is expected to succeed; the fact that the numbers match is only a coincidence.) See the
   * comment below for how to restore the fast but hang-y version.
   */
  @J2ktIncompatible
  @GwtIncompatible // used only in GwtIncompatible tests
  private static List<String> conditionalPseudoTimedGetUninterruptibly(

   * roughly) 2.5s longer. (2.5s is also the maximum length of time we will wait for a timed get
   * that is expected to succeed; the fact that the numbers match is only a coincidence.) See the
   * comment below for how to restore the fast but hang-y version.
   */
  @J2ktIncompatible
  @GwtIncompatible // used only in GwtIncompatible tests
  private static List<String> conditionalPseudoTimedGetUninterruptibly(

  }

  private @Nullable Object[] requireValues() {
    return requireNonNull(values);
  }

  /*
   * The following methods are safe to call as long as the conditions in the *previous* comment are
   * met *and* the index is less than size().
   *
   * (The above explains when these methods are safe from a `nullness` perspective. From an

    keyToRemove = map.keySet().iterator().next();
    if (supportsRemove) {
      int initialSize = map.size();
      map.get(keyToRemove);
      map.remove(keyToRemove);
      // This line doesn't hold - see the Javadoc comments above.
      // assertEquals(expectedValue, oldValue);
      assertFalse(map.containsKey(keyToRemove));
      assertEquals(initialSize - 1, map.size());
    } else {
      try {
        map.remove(keyToRemove);

  /** Returns the string representation generated by the delegate's {@code toString} method. */
  @Override
  public String toString() {
    return delegate().toString();
  }

  /* No equals or hashCode. See class comments for details. */