code: func (s *SecureChannelSession) open() (*responseAPDU, error) {
  	return transmit(s.card, &commandAPDU{
  		Cla:  claSCWallet,
  		Ins:  insOpenSecureChannel,
  		P1:   s.PairingIndex,
  		P2:   0,
  		Data: s.publicKey,
  		Le:   0,
  	})
  }
docs: // open is an internal method that sends an open APDU.