* range sets a and b, the result of {@code a.add(range)} is that {@code a} will be the minimal
   * range set for which both {@code a.enclosesAll(b)} and {@code a.encloses(range)}.
   *
   * <p>Note that {@code range} will be {@linkplain Range#span(Range) coalesced} with any ranges in
   * the range set that are {@linkplain Range#isConnected(Range) connected} with it. Moreover, if
   * {@code range} is empty, this is a no-op.

  }

  /**
   * 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 {

    assertTrue(range.encloses(Range.closed(3, 4)));

    assertFalse(range.encloses(Range.openClosed(2, 5)));
    assertFalse(range.encloses(Range.closedOpen(2, 5)));
    assertFalse(range.encloses(Range.closed(1, 4)));
    assertFalse(range.encloses(Range.closed(3, 6)));
    assertFalse(range.encloses(Range.greaterThan(3)));
    assertFalse(range.encloses(Range.lessThan(3)));
    assertFalse(range.encloses(Range.atLeast(3)));

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

        new ImmutableRangeMap.Builder<Integer, Integer>()
            .put(Range.closed(2, 4), 5)
            .put(Range.open(6, 7), 3)
            .put(Range.closedOpen(8, 10), 4)
            .put(Range.openClosed(15, 17), 2)
            .build();

    ImmutableMap<Range<Integer>, Integer> test = nonEmptyRangeMap.asMapOfRanges();

    for (Range<Integer> range : test.keySet()) {
      SerializableTester.reserializeAndAssert(range);

        && priorEntry.getValue().isConnected(range)
        && !priorEntry.getValue().intersection(range).isEmpty();
  }

  @Override
  public boolean encloses(Range<C> range) {
    checkNotNull(range);
    Entry<Cut<C>, Range<C>> floorEntry = rangesByLowerBound.floorEntry(range.lowerBound);
    return floorEntry != null && floorEntry.getValue().encloses(range);
  }

  private @Nullable Range<C> rangeEnclosing(Range<C> range) {

        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)));

    assertEquals(Range.closed(1, 3), ContiguousSet.closedOpen(1, 4).range());
    assertEquals(Range.closed(1, 3), ContiguousSet.create(Range.open(0, 4), integers()).range());
    assertEquals(
        Range.closed(1, 3), ContiguousSet.create(Range.openClosed(0, 3), integers()).range());

    assertEquals(
        Range.openClosed(0, 3),
        ContiguousSet.create(Range.closed(1, 3), integers()).range(OPEN, CLOSED));

   * the range map, or {@code null} otherwise.
   */
  @Nullable Entry<Range<K>, V> getEntry(K key);

  /**
   * Returns the minimal range {@linkplain Range#encloses(Range) enclosing} the ranges in this
   * {@code RangeMap}.
   *
   * @throws NoSuchElementException if this range map is empty
   */
  Range<K> span();

  /**

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