code: private void respondToListRecords(Map<String, String> args,
                                        String baseURL,
                                        List<?> records,
                                        ResumptionToken resumptionToken,
                                        PrintWriter out) {
          appendTop(out);
          appendRequest(args, baseURL, out);
          out.println("  <ListRecords>");
          for (int i = 0; i < records.size(); i++) {
              appendRecord("    ", (Record) records.get(i), out);
          }
          appendResumptionToken(resumptionToken, out);
          out.println("  </ListRecords>");
          appendBottom(out);
      }
docs: resumptionToken may be null