*
 * <pre>{@code
 * RangeSet<Integer> rangeSet = TreeRangeSet.create();
 * rangeSet.add(Range.closed(1, 10)); // {[1, 10]}
 * rangeSet.add(Range.closedOpen(11, 15)); // disconnected range; {[1, 10], [11, 15)}
 * rangeSet.add(Range.closedOpen(15, 20)); // connected range; {[1, 10], [11, 20)}
 * rangeSet.add(Range.openClosed(0, 0)); // empty range; {[1, 10], [11, 20)}

    assertEquals(set, Sets.subSet(set, Range.closedOpen(0, 12)));
    assertEquals(ImmutableSortedSet.of(2), Sets.subSet(set, Range.closedOpen(0, 4)));
    assertEquals(ImmutableSortedSet.of(2, 4), Sets.subSet(set, Range.closedOpen(2, 6)));
    assertEquals(ImmutableSortedSet.of(4, 6), Sets.subSet(set, Range.closedOpen(3, 7)));
    assertEquals(empty, Sets.subSet(set, Range.closedOpen(20, 30)));
  }

 * <tr><td>{@code (a..b]}  <td>{@code {x | a < x <= b}} <td>{@link Range#openClosed openClosed}
 * <tr><td>{@code [a..b)}  <td>{@code {x | a <= x < b}} <td>{@link Range#closedOpen closedOpen}
 * <tr><td>{@code (a..+∞)} <td>{@code {x | x > a}}      <td>{@link Range#greaterThan greaterThan}
 * <tr><td>{@code [a..+∞)} <td>{@code {x | x >= a}}     <td>{@link Range#atLeast atLeast}

 * <tr><td>{@code (a..b]}  <td>{@code {x | a < x <= b}} <td>{@link Range#openClosed openClosed}
 * <tr><td>{@code [a..b)}  <td>{@code {x | a <= x < b}} <td>{@link Range#closedOpen closedOpen}
 * <tr><td>{@code (a..+∞)} <td>{@code {x | x > a}}      <td>{@link Range#greaterThan greaterThan}
 * <tr><td>{@code [a..+∞)} <td>{@code {x | x >= a}}     <td>{@link Range#atLeast atLeast}

       */
      for (int i = 0; i < elements.size() - 1; i++) {
        assertEquals(elements.get(i) + 1, (int) elements.get(i + 1));
      }
      Range<Integer> range =
          elements.isEmpty() ? Range.closedOpen(0, 0) : Range.encloseAll(elements);
      return ContiguousSet.create(range, DiscreteDomain.integers());
    }
  }

       */
      for (int i = 0; i < elements.size() - 1; i++) {
        assertEquals(elements.get(i) + 1, (int) elements.get(i + 1));
      }
      Range<Integer> range =
          elements.isEmpty() ? Range.closedOpen(0, 0) : Range.encloseAll(elements);
      return ContiguousSet.create(range, DiscreteDomain.integers());
    }
  }