public void testEmptyEnclosing() {
    testEnclosing(TreeRangeSet.<Integer>create());
    testEnclosing(TreeRangeSet.<Integer>create().complement());
  }

  public void testAllSingleRangesEnclosing() {
    for (Range<Integer> range : QUERY_RANGES) {
      TreeRangeSet<Integer> rangeSet = TreeRangeSet.create();
      rangeSet.add(range);
      testEnclosing(rangeSet);
      testEnclosing(rangeSet.complement());
    }
  }