code: func (k *Kite) Port() int {
  	if k.listener == nil {
  		return 0
  	}
  
  	return k.listener.Addr().(*net.TCPAddr).Port
  }
docs: // Port returns the TCP port number that the kite listens.
  // Port must be called after the listener is initialized.
  // You can use ServerReadyNotify function to get notified when listener is ready.
  //
  // Kite starts to listen the port when Run() is called.
  // Since Run() is blocking you need to run it as a goroutine the call this function when listener is ready.
  //
  // Example:
  //
  //   k := kite.New("x", "1.0.0")
  //   go k.Run()
  //   <-k.ServerReadyNotify()
  //   port := k.Port()
  //