assertThrows(
        UnsupportedOperationException.class,
        () -> rangeSet.addAll(ImmutableRangeSet.<Integer>of()));
  }

  @SuppressWarnings("DoNotCall")
  public void testRemoveUnsupported() {
    RangeSet<Integer> rangeSet =
        ImmutableRangeSet.<Integer>builder()
            .add(Range.closed(5, 8))
            .add(Range.closedOpen(1, 3))
            .build();