Logo on the middle ? about qrcode HOT 2 OPEN

private func generateQRCode(str: String) -> UIImage? {
        guard var qrCode = QRCode(str) else {
            return nil
        }
        qrCode.errorCorrection = .High
        guard let qrImage = qrCode.image, let logoImage = UIImage(named: "logo") else {
            return nil
        }

        let logoWidth = qrImage.size.width / 4
        UIGraphicsBeginImageContextWithOptions(qrImage.size, false, 0)
        qrImage.draw(in: CGRect(origin: .zero, size: qrImage.size))
        logoImage.draw(in: CGRect(x: (qrImage.size.width - logoWidth) / 2, y: (qrImage.size.width - logoWidth) / 2,
                                  width: logoWidth, height: logoWidth))
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return image
    }