// we already know that should be kept.
    for (int n = list.size() - 1; n > from; n--) {
      if (predicate.apply(list.get(n))) {
        list.remove(n);
      }
    }
    // And now remove everything in the range [to, from) (going backwards).
    for (int n = from - 1; n >= to; n--) {
      list.remove(n);
    }
  }

  /** Removes and returns the first matching element, or returns {@code null} if there is none. */

   *     Remainder Operator</a>
   */
  @GwtIncompatible // TODO
  public static int mod(long x, int m) {
    // Cast is safe because the result is guaranteed in the range [0, m)
    return (int) mod(x, (long) m);
  }

  /**
   * Returns {@code x mod m}, a non-negative value less than {@code m}. This differs from {@code x %
   * m}, which might be negative.
   *

    assertTrue(rangeSet.intersects(Range.closed(3, 4)));
    assertTrue(rangeSet.intersects(Range.closedOpen(0, 2)));
    assertTrue(rangeSet.intersects(Range.closedOpen(3, 7)));
    assertTrue(rangeSet.intersects(Range.greaterThan(2)));
    assertFalse(rangeSet.intersects(Range.greaterThan(7)));

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

   * 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.

        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);

        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);

    for (Range<C> range : asRanges) {
      assertFalse(range.isEmpty());
    }

    // test that the RangeSet's span is the span of all the ranges
    Iterator<Range<C>> itr = rangeSet.asRanges().iterator();
    Range<C> expectedSpan = null;
    if (itr.hasNext()) {
      expectedSpan = itr.next();
      while (itr.hasNext()) {
        expectedSpan = expectedSpan.span(itr.next());
      }
    }

    try {