code: func (b *Bwhatsapp) Login() error {
  	b.Log.Debugln("Logging in..")
  
  	invert := b.GetBool(qrOnWhiteTerminal) // false is the default
  	qrChan := qrFromTerminal(invert)
  
  	session, err := b.conn.Login(qrChan)
  	if err != nil {
  		b.Log.Warnln("Failed to log in:", err)
  		return err
  	}
  	b.session = &session
  
  	b.Log.Infof("Logged into session: %#v", session)
  	b.Log.Infof("Connection: %#v", b.conn)
  
  	err = b.writeSession(session)
  	if err != nil {
  		fmt.Fprintf(os.Stderr, "error saving session: %v\n", err)
  	}
  
  	// TODO change connection strings to configured ones longClientName:"github.com/rhymen/go-whatsapp", shortClientName:"go-whatsapp"}" prefix=whatsapp
  	// TODO get also a nice logo
  
  	// TODO notification about unplugged and dead battery
  	// conn.Info: Wid, Pushname, Connected, Battery, Plugged
  
  	return nil
  }
docs: // Login to WhatsApp creating a new session. This will require to scan a QR code on your mobile device