.add("in", "the", "quick", "jumped", "over", "a")
            .build();
    assertTrue(set.headSet("a") instanceof ImmutableSortedSet);
    assertTrue(set.headSet("fish") instanceof ImmutableSortedSet);
    assertThat(set.headSet("fish")).containsExactly("a", "in", "the").inOrder();
    assertThat(set.headSet("california"))
        .containsExactly("a", "in", "the", "over", "quick", "jumped")
        .inOrder();

   * override {@link #equals} to forward to this implementation.
   *
   * @since 7.0
   */
  protected boolean standardEquals(@Nullable Object object) {
    return Multisets.equalsImpl(this, object);
  }

  /**
   * A sensible definition of {@link #hashCode} as {@code entrySet().hashCode()} . If you override

   * forward to this implementation.
   */
  protected @Nullable Entry<K, V> standardFirstEntry() {
    return Iterables.<@Nullable Entry<K, V>>getFirst(entrySet(), null);
  }

  /**
   * A sensible definition of {@link #firstKey} in terms of {@code firstEntry}. If you override
   * {@code firstEntry}, you may wish to override {@code firstKey} to forward to this

   * forward to this implementation.
   */
  protected @Nullable Entry<K, V> standardFirstEntry() {
    return Iterables.<@Nullable Entry<K, V>>getFirst(entrySet(), null);
  }

  /**
   * A sensible definition of {@link #firstKey} in terms of {@code firstEntry}. If you override
   * {@code firstEntry}, you may wish to override {@code firstKey} to forward to this

   * A sensible, albeit inefficient, definition of {@link #remove} in terms of the {@code iterator}
   * method of {@link #entrySet}. If you override {@link #entrySet}, you may wish to override {@link
   * #remove} to forward to this implementation.
   *
   * <p>Alternately, you may wish to override {@link #remove} with {@code keySet().remove}, assuming
   * that approach would not lead to an infinite loop.
   *
   * @since 7.0
   */

   * order. The sorting algorithm used is stable, so elements that compare as equal will stay in the
   * order in which they appear in the input.
   *
   * <p>If your data has no duplicates, or you wish to deduplicate elements, use {@code
   * ImmutableSortedSet.copyOf(elements)}; if you want a {@code List} you can use its {@code
   * asList()} view.
   *

 *   <li>{@link TreeMultiset}
 *   <li>{@link EnumMultiset}
 *   <li>{@link ConcurrentHashMultiset}
 * </ul>
 *
 * <p>If your values may be zero, negative, or outside the range of an int, you may wish to use
 * {@link com.google.common.util.concurrent.AtomicLongMap} instead. Note, however, that unlike
 * {@code Multiset}, {@code AtomicLongMap} does not automatically remove zeros.
 *

 *   <li>{@link TreeMultiset}
 *   <li>{@link EnumMultiset}
 *   <li>{@link ConcurrentHashMultiset}
 * </ul>
 *
 * <p>If your values may be zero, negative, or outside the range of an int, you may wish to use
 * {@link com.google.common.util.concurrent.AtomicLongMap} instead. Note, however, that unlike
 * {@code Multiset}, {@code AtomicLongMap} does not automatically remove zeros.
 *

class WebSocketReaderTest {
  private val data = Buffer()
  private val callback = WebSocketRecorder("client")
  private val random = Random(0)

  // Mutually exclusive. Use the one corresponding to the peer whose behavior you wish to test.
  private val serverReader =
    WebSocketReader(
      isClient = false,
      source = data,
      frameCallback = callback.asFrameCallback(),
      perMessageDeflate = false,

 * atomic unless otherwise noted.
 *
 * <p>Instances of this class are serializable if the keys are serializable.
 *
 * <p><b>Note:</b> If your values are always positive and less than 2^31, you may wish to use a
 * {@link com.google.common.collect.Multiset} such as {@link
 * com.google.common.collect.ConcurrentHashMultiset} instead.
 *