boolean isEmpty();

  /**
   * Returns the minimal range which {@linkplain Range#encloses(Range) encloses} all ranges in this
   * range set.
   *
   * @throws NoSuchElementException if this range set is {@linkplain #isEmpty() empty}
   */
  Range<C> span();

  // Views

  /**
   * Returns a view of the {@linkplain Range#isConnected disconnected} ranges that make up this

    }
  }

  @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 Range.create(firstRange.lowerBound, lastRange.upperBound);
  }

  /**
   * Guaranteed to throw an exception and leave the {@code RangeMap} unmodified.

  @GwtIncompatible // java.math.BigInteger
  public void testMean() {
    // Odd-sized ranges have an obvious mean
    assertMean(2, 1, 3);

    assertMean(-2, -3, -1);
    assertMean(0, -1, 1);
    assertMean(1, -1, 3);
    assertMean((1 << 30) - 1, -1, Integer.MAX_VALUE);

    // Even-sized ranges should prefer the lower mean
    assertMean(2, 1, 4);
    assertMean(-3, -4, -1);
    assertMean(0, -1, 2);

          RangeMap<Integer, Integer> rangemap =
              ImmutableRangeMap.<Integer, Integer>builder().put(range1, 1).put(range2, 2).build();
          assertEquals(range1.span(range2), rangemap.span());
        }
      }
    }
  }

  public void testGetEntry() {
    for (Range<Integer> range1 : RANGES) {
      for (Range<Integer> range2 : RANGES) {

    return getSubMap(0, keySet.headIndex(checkNotNull(toKey), inclusive));
  }

  /**
   * This method returns a {@code ImmutableSortedMap}, consisting of the entries whose keys ranges
   * from {@code fromKey}, inclusive, to {@code toKey}, exclusive.
   *
   * <p>The {@link SortedMap#subMap} documentation states that a submap of a submap throws an {@link

      for (Range<Integer> range2 : RANGES) {
        for (Range<Integer> range3 : RANGES) {
          Map<Integer, Integer> model = Maps.newHashMap();
          putModel(model, range1, 1);
          putModel(model, range2, 2);
          putModel(model, range3, 3);
          RangeMap<Integer, Integer> test = TreeRangeMap.create();
          RangeMap<Integer, Integer> test2 = TreeRangeMap.create();

  }

  /**
   * This test attempts to cause a future to wait for longer than it was requested to from a timed
   * get() call. As measurements of time are prone to flakiness, it tries to assert based on ranges
   * derived from observing how much time actually passed for various operations.
   */
  @SuppressWarnings({"DeprecatedThreadMethods", "ThreadPriorityCheck"})
  @AndroidIncompatible // Thread.suspend

  /**
   * Returns the range containing this key and its associated value, if such a range is present in
   * the range map, or {@code null} otherwise.
   */
  @CheckForNull
  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();

  /**

   * Range#contains contained} by the range.
   *
   * @throws IllegalArgumentException if neither range nor the domain has a lower bound, or if
   *     neither has an upper bound
   * @since 13.0
   */
  public static <C extends Comparable> ContiguousSet<C> create(
      Range<C> range, DiscreteDomain<C> domain) {
    checkNotNull(range);
    checkNotNull(domain);

   * works better than Ordering.natural().nullsFirst() because, if null comes before all other
   * values, it lies outside the submap/submultiset ranges we test, and the variety of tests that
   * exercise null handling fail on those subcollections.
   */
  public abstract static class NullsBefore implements Comparator<@Nullable String>, Serializable {
    /*