private void handleBytes(HttpServerExchange exchange, byte[] message) {
      try {
        callback.handle(exchange, message);
      } catch (Throwable ex) {
        exchange.setStatusCode(500);
        exchange.getResponseHeaders().put(Headers.CONTENT_TYPE, "text/plain");
        exchange.getResponseSender().send(ex.getMessage());
      }
    }
Returns server connect URL.

@return listining server's url.
form/src/test/java/feign/form/utils/UndertowServer.java