@GwtIncompatible
abstract class AbstractRangeSet<C extends Comparable> implements RangeSet<C> {
  AbstractRangeSet() {}

  @Override
  public boolean contains(C value) {
    return rangeContaining(value) != null;
  }

  @Override
  public abstract @Nullable Range<C> rangeContaining(C value);

  @Override
  public boolean isEmpty() {
    return asRanges().isEmpty();
  }

  @Override
  public void add(Range<C> range) {

@GwtIncompatible
abstract class AbstractRangeSet<C extends Comparable> implements RangeSet<C> {
  AbstractRangeSet() {}

  @Override
  public boolean contains(C value) {
    return rangeContaining(value) != null;
  }

  @Override
  public abstract @Nullable Range<C> rangeContaining(C value);

  @Override
  public boolean isEmpty() {
    return asRanges().isEmpty();
  }

  @Override
  public void add(Range<C> range) {

      }
      return false;
    }

    @Override
    public @Nullable Range<C> rangeContaining(C value) {
      if (!restriction.contains(value)) {
        return null;
      }
      Range<C> result = TreeRangeSet.this.rangeContaining(value);
      return (result == null) ? null : result.intersection(restriction);
    }

    @Override

  /**
   * Returns the unique range from this range set that {@linkplain Range#contains contains} {@code
   * value}, or {@code null} if this range set does not contain {@code value}.
   */
  @Nullable Range<C> rangeContaining(C value);

  /**
   * Returns {@code true} if there exists a non-empty range enclosed by both a member range in this
   * range set and the specified range. This is equivalent to calling {@code

  /**
   * Returns the unique range from this range set that {@linkplain Range#contains contains} {@code
   * value}, or {@code null} if this range set does not contain {@code value}.
   */
  @Nullable Range<C> rangeContaining(C value);

  /**
   * Returns {@code true} if there exists a non-empty range enclosed by both a member range in this
   * range set and the specified range. This is equivalent to calling {@code

            Ordering.natural(),
            ANY_PRESENT,
            NEXT_LOWER);
    return index != -1 && ranges.get(index).encloses(otherRange);
  }

  @Override
  public @Nullable Range<C> rangeContaining(C value) {
    int index =
        SortedLists.binarySearch(
            ranges,
            Range::lowerBound,
            Cut.belowValue(value),
            Ordering.natural(),
            ANY_PRESENT,

            Ordering.natural(),
            ANY_PRESENT,
            NEXT_LOWER);
    return index != -1 && ranges.get(index).encloses(otherRange);
  }

  @Override
  public @Nullable Range<C> rangeContaining(C value) {
    int index =
        SortedLists.binarySearch(
            ranges,
            Range::lowerBound,
            Cut.belowValue(value),
            Ordering.natural(),
            ANY_PRESENT,

    rangeSet.remove(Range.open(5, 7));
    assertEquals(Range.closed(3, 5), rangeSet.rangeContaining(5));
    assertTrue(rangeSet.contains(5));
    assertEquals(Range.closed(7, 10), rangeSet.rangeContaining(8));
    assertTrue(rangeSet.contains(8));
    assertThat(rangeSet.rangeContaining(6)).isNull();
    assertFalse(rangeSet.contains(6));
  }

  public void testAddAll() {