void Server::WorkerRoutine() {
  LOG_INFO("Worker is running");

  for (;;) {
    auto connection = queue_.PopOrWait();

    if (!connection) {
      LOG_INFO("Worker is going to stop");

      // For stopping next worker.
      queue_.Push({});

      // Stop this worker.
      break;
    }

    Handle(connection);
  }
}
void Server::WorkerRoutine() {
  LOG_INFO("Worker is running");

  for (;;) {
    auto connection = queue_.PopOrWait();

    if (!connection) {
      LOG_INFO("Worker is going to stop");

       
      queue_.Push({});

       
      break;
    }

    Handle(connection);
  }
}