* TODO(kevinb): evaluate the trade-offs of going bimorphic to save these two fields from most
   * instances. Note that the instances that would get smaller are the right set to care about
   * optimizing, because the rest have the option of calling `trimmed`.
   */

  private final transient int start; // it happens that we only serialize instances where this is 0
  private final int end; // exclusive

  private ImmutableLongArray(long[] array) {

   * Splitter.on(',').omitEmptyStrings().split(",a,,,b,c,,")} returns an iterable containing only
   * {@code ["a", "b", "c"]}.
   *
   * <p>If either {@code trimResults} option is also specified when creating a splitter, that
   * splitter always trims results first before checking for emptiness. So, for example, {@code

   *
   * <p><b>{@code Stream} equivalent:</b> {@code stream.filter(type::isInstance).map(type::cast)}.
   * This does perform a little more work than necessary, so another option is to insert an
   * unchecked cast at some later point:
   *
   * <pre>
   * {@code @SuppressWarnings("unchecked") // safe because of ::isInstance check
   * ImmutableList<NewType> result =

   *
   * <p><b>{@code Stream} equivalent:</b> {@code stream.filter(type::isInstance).map(type::cast)}.
   * This does perform a little more work than necessary, so another option is to insert an
   * unchecked cast at some later point:
   *
   * <pre>
   * {@code @SuppressWarnings("unchecked") // safe because of ::isInstance check
   * ImmutableList<NewType> result =

   * than this method, and this method in turn generally performs better than copying the list and
   * calling {@link Collections#sort(List)}.
   */
  // TODO(kevinb): rerun benchmarks including new options
  @SuppressWarnings("nullness") // TODO: b/316358623 - Remove after checker fix.
  public <E extends T> List<E> sortedCopy(Iterable<E> elements) {
    @SuppressWarnings("unchecked") // does not escape, and contains only E's

    // Plug the following UnicodeSet pattern into
    // https://unicode.org/cldr/utility/list-unicodeset.jsp
    // [[[:Zs:][:Zl:][:Zp:][:Cc:][:Cf:][:Cs:][:Co:]]&[\u0000-\uFFFF]]
    // with the "Abbreviate" option, and get the ranges from there.
    private static final String RANGE_STARTS =
        "\u0000\u007f\u00ad\u0600\u061c\u06dd\u070f\u0890\u08e2\u1680\u180e\u2000\u2028\u205f\u2066"
            + "\u3000\ud800\ufeff\ufff9";

  private final ImmutableSet<TestOption> options;
  private boolean closed;

  public TestInputStream(InputStream in, TestOption... options) throws IOException {
    this(in, Arrays.asList(options));
  }

  public TestInputStream(InputStream in, Iterable<TestOption> options) throws IOException {
    super(checkNotNull(in));
    this.options = ImmutableSet.copyOf(options);
    throwIf(OPEN_THROWS);
  }

  private final ImmutableSet<TestOption> options;
  private boolean closed;

  public TestInputStream(InputStream in, TestOption... options) throws IOException {
    this(in, Arrays.asList(options));
  }

  public TestInputStream(InputStream in, Iterable<TestOption> options) throws IOException {
    super(checkNotNull(in));
    this.options = ImmutableSet.copyOf(options);
    throwIf(OPEN_THROWS);
  }

  private final ImmutableSet<TestOption> options;
  private boolean closed;

  public TestOutputStream(OutputStream out, TestOption... options) throws IOException {
    this(out, Arrays.asList(options));
  }

  public TestOutputStream(OutputStream out, Iterable<TestOption> options) throws IOException {
    super(checkNotNull(out));
    this.options = ImmutableSet.copyOf(options);
    throwIf(OPEN_THROWS);
  }

  private final byte[] bytes;
  private final ImmutableSet<TestOption> options;

  private boolean inputStreamOpened;
  private boolean inputStreamClosed;

  TestByteSource(byte[] bytes, TestOption... options) {
    this.bytes = checkNotNull(bytes);
    this.options = ImmutableSet.copyOf(options);
  }

  @Override
  public boolean wasStreamOpened() {
    return inputStreamOpened;
  }