Returns an immutable range set containing the specified single range. If {@link Range#isEmpty()
   * range.isEmpty()}, this is equivalent to {@link ImmutableRangeSet#of()}.
Returns an immutable range set containing the specified single range. If {@link Range#isEmpty()
   * range.isEmpty()}, this is equivalent to {@link ImmutableRangeSet#of()}. | ImmutableRangeSet.java