* values are null. This method may update {@code alternatingKeysAndValues} if there are duplicate
   * keys. If so, the return value will indicate how many entries are still valid, and will also
   * include a {@link Builder.DuplicateKey} in case duplicate keys are not allowed now or will not
   * be allowed on a later {@link Builder#buildOrThrow()} call.
   *

   * Section 7.2.1.2. The iteration order follows the lexicographical order. This means that the
   * first permutation will be in ascending order, and the last will be in descending order.
   *
   * <p>Duplicate elements are considered equal. For example, the list [1, 1] will have only one
   * permutation, instead of two. This is why the elements have to implement {@link Comparable}.
   *

   * Section 7.2.1.2. The iteration order follows the lexicographical order. This means that the
   * first permutation will be in ascending order, and the last will be in descending order.
   *
   * <p>Duplicate elements are considered equal. For example, the list [1, 1] will have only one
   * permutation, instead of two. This is why the elements have to implement {@link Comparable}.
   *

   * returned {@code ByteArrayDataOutput} and new data will be appended to any existing content.
   *
   * <p>Note that if the given output stream was not empty or is modified after the {@code
   * ByteArrayDataOutput} is created, the contract for {@link ByteArrayDataOutput#toByteArray} will
   * not be honored (the bytes returned in the byte array may not be exactly what was written via

 * versions would create a file that is more accessible, as discussed in <a
 * href="https://github.com/google/guava/issues/2575">Guava issue 2575</a>. TODO: b/283778848 - Fill
 * in CVE number once it's available.)
 *
 * <p>Temporary files created by this stream may live in the local filesystem until either:
 *
 * <ul>

   * containing one element (the given set itself).
   *
   * <p>Despite the method name, this method attempts to avoid actually copying the data when it is
   * safe to do so. The exact circumstances under which a copy will or will not be performed are
   * undocumented and subject to change.
   *
   * <p>This method is not type-safe, as it may be called on elements that are not mutually
   * comparable.
   *

      delegate.clear(); // invalidate any iterators left over!
      table = null;
      size = 0;
    } else {
      Arrays.fill(requireElements(), 0, size, null);
      CompactHashing.tableClear(requireTable());
      Arrays.fill(requireEntries(), 0, size, 0);
      this.size = 0;
    }
  }

  @J2ktIncompatible
  private void writeObject(ObjectOutputStream stream) throws IOException {

    // We consider elementData(index) a "hole", and we want to fill it
    // with the last element of the heap, toTrickle.
    // Since the last element of the heap is from the bottom level, we
    // optimistically fill index position with elements from lower levels,
    // moving the hole down. In most cases this reduces the number of
    // comparisons with toTrickle, but in some cases we will need to bubble it
    // all the way up again.

   *       created by invoking the constructor or static factory method.
   *   <li>If there is any non-private constructor or non-private static factory method declared by
   *       {@code cls}:
   *       <ul>
   *         <li>Test will fail if default value for a parameter cannot be determined.

   *
   * <p>If the elements contain duplicates (according to the comparator), only the first duplicate
   * in encounter order will appear in the result.
   */
  @SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})
  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  static <E> Collector<E, ?, ImmutableSortedSet<E>> toImmutableSortedSet(
      Comparator<? super E> comparator) {