code: func (l *RaftLayer) Handoff(c net.Conn) error {
  	select {
  	case l.connCh <- c:
  		return nil
  	case <-l.closeCh:
  		return fmt.Errorf("Raft RPC layer closed")
  	}
  }
docs: // Handoff is used to hand off a connection to the
  // RaftLayer. This allows it to be Accept()'ed