code: public static void compact(Set<String> source, Adder adder, boolean shorterPairs) {
          compact(source,adder,shorterPairs,false);
      }
docs: Faster but not as good compaction. Only looks at final codepoint.
  @param source set of strings
  @param adder adds each pair to the output. See the {@link Adder} interface.
  @param shorterPairs use abc-d instead of abc-abd