code: func (s *StanServer) startGoRoutine(f func()) {
  	s.mu.Lock()
  	if !s.shutdown {
  		s.wg.Add(1)
  		go f()
  	}
  	s.mu.Unlock()
  }
docs: // startGoRoutine starts the given function as a go routine if and only if
  // the server was not shutdown at that time. This is required because
  // we cannot increment the wait group after the shutdown process has started.