code: private static Map<String, List<String>> getOrCreateProtocolHeader(
              Message message) {
          Map<String, List<String>> headers = CastUtils.cast((Map<?, ?>) message
                  .get(Message.PROTOCOL_HEADERS));
          if (headers == null) {
              headers = new HashMap<String, List<String>>();
              message.put(Message.PROTOCOL_HEADERS, headers);
          }
          return headers;
      }
docs: Gets the or create protocol header.
  
  @param message the message
  @return the message headers map