long estimatedSize = 0L;
    ImmutableList.Builder<Spliterator.OfLong> splitrsBuilder =
        new ImmutableList.Builder<>(streams.length);
    for (LongStream stream : streams) {
      isParallel |= stream.isParallel();
      Spliterator.OfLong splitr = stream.spliterator();
      splitrsBuilder.add(splitr);
      characteristics &= splitr.characteristics();

     */
    @IgnoreJRERequirement // Users will use this only if they're already using streams.
    @CanIgnoreReturnValue
    public Builder addAll(LongStream stream) {
      Spliterator.OfLong spliterator = stream.spliterator();
      long size = spliterator.getExactSizeIfKnown();
      if (size > 0) { // known *and* nonempty
        ensureRoomFor(Ints.saturatedCast(size));
      }

    /*
     * This is an override that is not directly visible to callers, so NewApi will catch calls to
     * Collection.spliterator() where necessary.
     */
    @IgnoreJRERequirement
    public Spliterator.OfLong spliterator() {
      return Spliterators.spliterator(array, start, end, 0);
    }

    @Override
    public boolean contains(@Nullable Object target) {
      // Overridden to prevent a ton of boxing