int index = off;
    while (true) {
      int byte1;

      // Optimize for interior runs of ASCII bytes.
      do {
        if (index >= end) {
          return true;
        }
      } while ((byte1 = bytes[index++]) >= 0);

      if (byte1 < (byte) 0xE0) {
        // Two-byte form.
        if (index == end) {
          return false;
        }

    int index = off;
    while (true) {
      int byte1;

      // Optimize for interior runs of ASCII bytes.
      do {
        if (index >= end) {
          return true;
        }
      } while ((byte1 = bytes[index++]) >= 0);

      if (byte1 < (byte) 0xE0) {
        // Two-byte form.
        if (index == end) {
          return false;
        }

  }

  @Override
  public ImmutableList<E> get(int index) {
    checkElementIndex(index, size());
    return new ImmutableList<E>() {

      @Override
      public int size() {
        return axes.size();
      }

      @Override
      public E get(int axis) {
        checkElementIndex(axis, size());
        int axisIndex = getAxisIndexForProductIndex(index, axis);
        return axes.get(axis).get(axisIndex);

  }

  @Override
  @CheckForNull
  public E lower(E element) {
    int index = headIndex(element, false) - 1;
    return (index == -1) ? null : elements.get(index);
  }

  @Override
  @CheckForNull
  public E floor(E element) {
    int index = headIndex(element, true) - 1;
    return (index == -1) ? null : elements.get(index);
  }

  @Override
  @CheckForNull
  public E ceiling(E element) {

   */
  static void tableSet(Object table, int index, int entry) {
    if (table instanceof byte[]) {
      ((byte[]) table)[index] = (byte) entry; // unsigned write
    } else if (table instanceof short[]) {
      ((short[]) table)[index] = (short) entry; // unsigned write
    } else {
      ((int[]) table)[index] = entry;
    }
  }

  /**

     */
    @Override
    public String escape(String s) {
      int slen = s.length();
      for (int index = 0; index < slen; index++) {
        char c = s.charAt(index);
        if (c < replacements.length && replacements[c] != null) {
          return escapeSlow(s, index);
        }
      }
      return s;
    }

    @Override
    @CheckForNull
    protected char[] escape(char c) {

   *
   * @param stack The prefixes that precede the characters represented by this node. Each entry of
   *     the stack is in reverse order.
   * @param encoded The serialized trie.
   * @param start An index in the encoded serialized trie to begin reading characters from.
   * @param builder A map builder to which all entries will be added.
   * @return The number of characters consumed from {@code encoded}.
   */

  }

  private void doTestSet(E newValue) {
    int index = aValidIndex();
    E initialValue = getList().get(index);
    assertEquals(
        "set(i, x) should return the old element at position i.",
        initialValue,
        getList().set(index, newValue));
    assertEquals("After set(i, x), get(i) should return x", newValue, getList().get(index));

  private final transient int hashCode;
  // the same values as `elements` in hashed positions (plus nulls)
  @VisibleForTesting final transient @Nullable Object[] table;
  // 'and' with an int to get a valid table index.
  private final transient int mask;
  private final transient int size;

  RegularImmutableSet(
      @Nullable Object[] elements, int hashCode, @Nullable Object[] table, int mask, int size) {

  public E higher(E element) {
    return forward.lower(element);
  }

  @Override
  int indexOf(@CheckForNull Object target) {
    int index = forward.indexOf(target);
    if (index == -1) {
      return index;
    } else {
      return size() - 1 - index;
    }
  }

  @Override
  boolean isPartialView() {
    return forward.isPartialView();
  }