return delegateCollection().comparator();
  }

  // Override indexOf() and lastIndexOf() to be O(log N) instead of O(N).

  @GwtIncompatible // ImmutableSortedSet.indexOf
  // TODO(cpovirk): consider manual binary search under GWT to preserve O(log N) lookup
  @Override
  public int indexOf(@CheckForNull Object target) {
    int index = delegateCollection().indexOf(target);

                if (userAgent != null) {
                    if (userAgent.indexOf("MSIE") >= 0 || userAgent.indexOf("Trident") >= 0) {
                        uaType = UserAgentType.IE;
                    } else if (userAgent.indexOf("Firefox") >= 0) {
                        uaType = UserAgentType.FIREFOX;
                    } else if (userAgent.indexOf("Chrome") >= 0) {
                        uaType = UserAgentType.CHROME;

            int indexOf = field.indexOf(':');
            if (indexOf < 0)
                return new Pair<>(field, null);
            final String indexField = indexOf == 0 ? defaultField : field.substring(0, indexOf);
            final String extensionKey = field.substring(indexOf + 1);
            return new Pair<>(indexField, extensionKey);
        }
    }

  ForwardingImmutableList() {}

  abstract List<E> delegateList();

  public int indexOf(@Nullable Object object) {
    return delegateList().indexOf(object);
  }

  public int lastIndexOf(@Nullable Object object) {
    return delegateList().lastIndexOf(object);
  }

  public E get(int index) {
    return delegateList().get(index);
  }

  public ImmutableList<E> subList(int fromIndex, int toIndex) {

        String result = original;

        // Unquote
        if (result.indexOf('\"') >= 0) {
            final Matcher m = QUOTE_REPLACE_PATTERN.matcher(original);
            if (m.matches()) {
                result = m.group(1);
            }

            // Unescape
            if (result.indexOf(ESCAPED_QUOTE) >= 0) {
                result = result.replace(ESCAPED_QUOTE, "\"");
            }

    }
    this.axesSizeProduct = axesSizeProduct;
  }

  private int getAxisIndexForProductIndex(int index, int axis) {
    return (index / axesSizeProduct[axis + 1]) % axes.get(axis).size();
  }

  @Override
  public int indexOf(@CheckForNull Object o) {
    if (!(o instanceof List)) {
      return -1;
    }
    List<?> list = (List<?>) o;
    if (list.size() != axes.size()) {

        list.addLast("1");
        list.addLast("2");
        list.addLast("3");
        assertThat(list.indexOf(null), is(0));
        assertThat(list.indexOf("1"), is(1));
        assertThat(list.indexOf("2"), is(2));
        assertThat(list.indexOf("3"), is(3));
        assertThat(list.indexOf("4"), is(-1));
    }

  @Override
  @CheckForNull
  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();
  }

      int answer,
      KeyPresentBehavior presentBehavior,
      KeyAbsentBehavior absentBehavior) {
    switch (presentBehavior) {
      case FIRST_PRESENT:
        if (list.contains(key)) {
          assertEquals(list.indexOf(key), answer);
          return;
        }
        break;
      case LAST_PRESENT:
        if (list.contains(key)) {
          assertEquals(list.lastIndexOf(key), answer);
          return;
        }

        throw IllegalArgumentException(e)
      }
    } else {
      this.handshake = null
    }

    if (requestLine.isNotEmpty()) {
      val methodEnd = requestLine.indexOf(' ')
      val pathEnd = requestLine.indexOf(' ', methodEnd + 1)
      this.method = requestLine.substring(0, methodEnd)
      var path = requestLine.substring(methodEnd + 1, pathEnd)
      if (!path.startsWith("/")) {
        path = "/"