docs: public static void main(String[] args) throws IOException, InterruptedException {
  
          if (args.length < 4 || args.length > 5) {
              System.out.println(
                      "USAGE: HelloWorldServerTls host port certChainFilePath privateKeyFilePath " +
                      "[trustCertCollectionFilePath]\n  Note: You only need to supply trustCertCollectionFilePath if you want " +
                      "to enable Mutual TLS.");
              System.exit(0);
          }
  
          final HelloWorldServerTls server = new HelloWorldServerTls(args[0],
                  Integer.parseInt(args[1]),
                  args[2],
                  args[3],
                  args.length == 5 ? args[4] : null);
          server.start();
          server.blockUntilShutdown();
      }