code: public static String readFlowId(Message message) {
          String flowId = null;
          Map<String, List<String>> headers = getOrCreateProtocolHeader(message);
          List<String> flowIds = headers.get(FLOWID_HTTP_HEADER_NAME);
          if (flowIds != null && flowIds.size() > 0) {
              flowId = flowIds.get(0);
              if (LOG.isLoggable(Level.FINE)) {
                  LOG.fine("HTTP header '" + FLOWID_HTTP_HEADER_NAME + "' found: " + flowId);
              }
          } else {
              if (LOG.isLoggable(Level.FINE)) {
                  LOG.fine("No HTTP header '" + FLOWID_HTTP_HEADER_NAME + "' found");
              }
          }
  
          return flowId;
      }
docs: Read flow id from message.
  
  @param message the message
  @return the FlowId as string