code: public static void main(String[] args) throws Exception {
      boolean usage = false;
      int serverPort = 0;
      int driverPort = 0;
      for (String arg : args) {
        if (!arg.startsWith("--")) {
          System.err.println("All arguments must start with '--': " + arg);
          usage = true;
          break;
        }
        String[] parts = arg.substring(2).split("=", 2);
        String key = parts[0];
        if ("help".equals(key)) {
          usage = true;
          break;
        }
        if (parts.length != 2) {
          System.err.println("All arguments must be of the form --arg=value");
          usage = true;
          break;
        }
        String value = parts[1];
        if ("server_port".equals(key)) {
          serverPort = Integer.valueOf(value);
        } else if ("driver_port".equals(key)) {
          driverPort = Integer.valueOf(value);
        } else {
          System.err.println("Unknown argument: " + key);
          usage = true;
          break;
        }
      }
      if (usage || driverPort == 0) {
        System.err.println(
            "Usage: [ARGS...]"
                + "\n"
                + "\n  --driver_port=<port>"
                + "\n    Port to expose grpc.testing.WorkerService, used by driver to initiate work."
                + "\n  --server_port=<port>"
                + "\n    Port to start load servers on. Defaults to any available port");
        System.exit(1);
      }
  
  
      // important to enable HTTP/2 in ActorSystem's config
      Config conf = ConfigFactory.parseString("akka.http.server.preview.enable-http2 = on")
          .withFallback(ConfigFactory.defaultApplication());
      ActorSystem system = ActorSystem.create("LoadWorker", conf);
      new LoadWorker(system, driverPort, serverPort).start();
    }
docs: Start the load worker process.