* Range#isConnected(Range) disconnected} ranges of type {@code C}.
 *
 * <p>Implementations that choose to support the {@link #add(Range)} operation are required to
 * ignore empty ranges and coalesce connected ranges. For example:
 *
 * {@snippet :
 * RangeSet<Integer> rangeSet = TreeRangeSet.create();
 * rangeSet.add(Range.closed(1, 10)); // {[1, 10]}