docs: @Override
      public void getResult(final ContentHandler buf) throws SAXException {
          final String separator = paramTable.getOrDefault("separator", "|");
          final List<String> v = valueSet.stream()
                  .map(fileValue -> fileValue.value)
                  .distinct()
                  .collect(Collectors.toList());
          Collections.sort(v);
          final StringBuilder retBuf = new StringBuilder();
          for (final Iterator<String> i = v.iterator(); i.hasNext();) {
              retBuf.append(i.next());
              if (i.hasNext()) {
                  retBuf.append(separator);
              }
          }
          final char[] ret = retBuf.toString().toCharArray();
          buf.characters(ret, 0, ret.length);
      }