docs: protected void checkHostUp(final String scheme, final String host, final int port, final HttpServerExchange exchange, final NodePingUtil.PingCallback callback) {
  
          final XnioSsl xnioSsl = null; // TODO
          final OptionMap options = OptionMap.builder()
                  .set(Options.TCP_NODELAY, true)
                  .getMap();
  
          try {
              // http, ajp and maybe more in future
              if ("ajp".equalsIgnoreCase(scheme) || "http".equalsIgnoreCase(scheme)) {
                  final URI uri = new URI(scheme, null, host, port, "/", null, null);
                  NodePingUtil.pingHttpClient(uri, callback, exchange, container.getClient(), xnioSsl, options);
              } else {
                  final InetSocketAddress address = new InetSocketAddress(host, port);
                  NodePingUtil.pingHost(address, exchange, callback, options);
              }
          } catch (URISyntaxException e) {
              callback.failed();
          }
      }