return null;
    } else {
      Range<K> range = ranges.get(index);
      return range.contains(key) ? Maps.immutableEntry(range, values.get(index)) : null;
    }
  }

  @Override
  public Range<K> span() {
    if (ranges.isEmpty()) {
      throw new NoSuchElementException();
    }
    Range<K> firstRange = ranges.get(0);
    Range<K> lastRange = ranges.get(ranges.size() - 1);

    assertEquals(ImmutableSortedSet.of(4), Sets.subSet(set, Range.open(2, 6)));
    assertEquals(ImmutableSortedSet.of(4, 6), Sets.subSet(set, Range.open(3, 7)));
    assertEquals(empty, Sets.subSet(set, Range.open(20, 30)));

    assertEquals(set, Sets.subSet(set, Range.openClosed(0, 12)));
    assertEquals(ImmutableSortedSet.of(2, 4), Sets.subSet(set, Range.openClosed(0, 4)));

  private final transient Reference<AvlNode<E>> rootReference;
  private final transient GeneralRange<E> range;
  private final transient AvlNode<E> header;

  TreeMultiset(Reference<AvlNode<E>> rootReference, GeneralRange<E> range, AvlNode<E> endLink) {
    super(range.comparator());
    this.rootReference = rootReference;
    this.range = range;
    this.header = endLink;
  }

  TreeMultiset(Comparator<? super E> comparator) {

        range.intersect(GeneralRange.<@Nullable Integer>range(ORDERING, null, OPEN, 5, CLOSED)));

    assertEquals(
        GeneralRange.range(ORDERING, 2, OPEN, 4, OPEN),
        range.intersect(GeneralRange.range(ORDERING, 2, OPEN, 5, CLOSED)));

    assertEquals(
        GeneralRange.range(ORDERING, 2, CLOSED, 4, OPEN),
        range.intersect(GeneralRange.range(ORDERING, 1, OPEN, 4, OPEN)));

  }

  /**
   * Returns an immutable range set containing the specified single range. If {@link Range#isEmpty()
   * range.isEmpty()}, this is equivalent to {@link ImmutableRangeSet#of()}.
   */
  public static <C extends Comparable> ImmutableRangeSet<C> of(Range<C> range) {
    checkNotNull(range);
    if (range.isEmpty()) {
      return of();
    } else if (range.equals(Range.all())) {
      return all();
    } else {

  }

  /**
   * Returns an immutable range set containing the specified single range. If {@link Range#isEmpty()
   * range.isEmpty()}, this is equivalent to {@link ImmutableRangeSet#of()}.
   */
  public static <C extends Comparable> ImmutableRangeSet<C> of(Range<C> range) {
    checkNotNull(range);
    if (range.isEmpty()) {
      return of();
    } else if (range.equals(Range.all())) {
      return all();
    } else {

      return null;
    } else {
      Range<K> range = ranges.get(index);
      return range.contains(key) ? Maps.immutableEntry(range, values.get(index)) : null;
    }
  }

  @Override
  public Range<K> span() {
    if (ranges.isEmpty()) {
      throw new NoSuchElementException();
    }
    Range<K> firstRange = ranges.get(0);
    Range<K> lastRange = ranges.get(ranges.size() - 1);

        return string;
      }
    };
  }

  @Empty
  static <C extends Comparable<?>> Range<C> generateRange() {
    return Range.all();
  }

  @Generates
  static <C extends Comparable<?>> Range<C> generateRange(C freshElement) {
    return Range.singleton(freshElement);
  }

  @Generates
  static <E> Iterable<E> generateIterable(@Nullable E freshElement) {

  private final int k;
  private final Comparator<? super T> comparator;

  /*
   * We are currently considering the elements in buffer in the range [0, bufferSize) as candidates
   * for the top k elements. Whenever the buffer is filled, we quickselect the top k elements to the
   * range [0, k) and ignore the remaining elements.
   */
  private final @Nullable T[] buffer;
  private int bufferSize;

  /**

 *
 * <h3>Only {@code %s} is supported</h3>
 *
 * <p>{@code Preconditions} uses {@link Strings#lenientFormat} to format error message template
 * strings. This only supports the {@code "%s"} specifier, not the full range of {@link
 * java.util.Formatter} specifiers. However, note that if the number of arguments does not match the
 * number of occurrences of {@code "%s"} in the format string, {@code Preconditions} will still