code: private static void appendResult(int result, Appendable dest,
              int cpLength, int options, Edits edits) throws IOException {
          // Decode the result.
          if (result < 0) {
              // (not) original code point
              if (edits != null) {
                  edits.addUnchanged(cpLength);
                  if ((options & OMIT_UNCHANGED_TEXT) != 0) {
                      return;
                  }
              }
              appendCodePoint(dest, ~result);
          } else if (result <= UCaseProps.MAX_STRING_LENGTH) {
              // The mapping has already been appended to result.
              if (edits != null) {
                  edits.addReplace(cpLength, result);
              }
          } else {
              // Append the single-code point mapping.
              int length = appendCodePoint(dest, result);
              if (edits != null) {
                  edits.addReplace(cpLength, length);
              }
          }
      }
docs: Appends a full case mapping result, see {@link UCaseProps#MAX_STRING_LENGTH}.
  @throws IOException