code: function startWorker(port) {
          var worker = child.fork(serverWorker, [
              '--port', port,
              '--server', serverFile,
              '--allowForcedExit', allowForcedExit,
              '--config', JSON.stringify(config.app || {}),
              '--title', workerTitle
          ]);
  
          worker.on('exit', createWorkerExitHandler(port));
          return worker;
      }
docs: Start a worker on a specific port
  @private