code: func (l *raftLayer) Dial(addr string, timeout time.Duration) (net.Conn, error) {
  	conn, err := net.DialTimeout("tcp", addr, timeout)
  	if err != nil {
  		return nil, err
  	}
  
  	// Write a header byte.
  	_, err = conn.Write([]byte{StoreHdr})
  	if err != nil {
  		conn.Close()
  		return nil, err
  	}
  	return conn, nil
  }
docs: // Dial creates a new network connection.