@NullMarked
public class RangeTest extends TestCase {
  public void testOpen() {
    Range<Integer> range = Range.open(4, 8);
    checkContains(range);
    assertTrue(range.hasLowerBound());
    assertEquals(4, (int) range.lowerEndpoint());
    assertEquals(OPEN, range.lowerBoundType());
    assertTrue(range.hasUpperBound());
    assertEquals(8, (int) range.upperEndpoint());
    assertEquals(OPEN, range.upperBoundType());
    assertFalse(range.isEmpty());

@NullMarked
public class RangeTest extends TestCase {
  public void testOpen() {
    Range<Integer> range = Range.open(4, 8);
    checkContains(range);
    assertTrue(range.hasLowerBound());
    assertEquals(4, (int) range.lowerEndpoint());
    assertEquals(OPEN, range.lowerBoundType());
    assertTrue(range.hasUpperBound());
    assertEquals(8, (int) range.upperEndpoint());
    assertEquals(OPEN, range.upperBoundType());
    assertFalse(range.isEmpty());

    if (other.isEmpty()) {
      return other;
    } else {
      C lowerEndpoint = Ordering.<C>natural().max(this.first(), other.first());
      C upperEndpoint = Ordering.<C>natural().min(this.last(), other.last());
      return (lowerEndpoint.compareTo(upperEndpoint) <= 0)
          ? ContiguousSet.create(Range.closed(lowerEndpoint, upperEndpoint), domain)
          : new EmptyContiguousSet<C>(domain);
    }
  }

        backingItr = rangesByLowerBound.values().iterator();
      } else {
        Entry<Cut<C>, Range<C>> lowerEntry =
            rangesByLowerBound.lowerEntry(upperBoundWindow.lowerEndpoint());
        if (lowerEntry == null) {
          backingItr = rangesByLowerBound.values().iterator();
        } else if (upperBoundWindow.lowerBound.isLessThan(lowerEntry.getValue().upperBound)) {

      checkArgument(
          set.comparator().compare(range.lowerEndpoint(), range.upperEndpoint()) <= 0,
          "set is using a custom comparator which is inconsistent with the natural ordering.");
    }
    if (range.hasLowerBound() && range.hasUpperBound()) {
      return set.subSet(
          range.lowerEndpoint(),
          range.lowerBoundType() == BoundType.CLOSED,
          range.upperEndpoint(),