code: func (s *MockCCComm) ka(done <-chan struct{}) {
  	for {
  		if s.keepAlive == nil {
  			return
  		}
  		s.Send(s.keepAlive)
  		select {
  		case <-time.After(10 * time.Millisecond):
  		case <-done:
  			return
  		}
  	}
  }
docs: //keepAlive