It doesn't take me to payUmoney payment page screen. I am getting this in console while adding PayUmoney payment gateway.   PayUmoney Integration[8923:268037] -[NSURL init] called; this results in an NSURL instance with an empty URL string. Please use one of the documented NSURL initialization methods instead (initWithString:, initFileURLWithPath:, etc.). This message shown only once. Here is my code. I already checked this How to integrate PayUMoney iOS SDK in swift project Thanks in advance.
import UIKit
class ViewController: UIViewController {
  let paymentParam: PayUModelPaymentParams  = PayUModelPaymentParams()
  var hashes :PayUModelHashes  = PayUModelHashes()
  let PUSAhelper:PUSAHelperClass = PUSAHelperClass()
  var PayUBaseUrl = "https://secure.payu.in"
  override func viewDidLoad() {
    super.viewDidLoad()
  }
  @IBAction func showPass(_ sender: UIButton) {
    self.continueWithCardPayment()
  }
  func continueWithCardPayment()  {
    paymentParam.key = "gtKFFx"
    paymentParam.transactionID = "txnID20170220"
    paymentParam.amount = "10.0"
    paymentParam.productInfo = "Nokia"
    paymentParam.surl = "https://payu.herokuapp.com/success"
    paymentParam.furl = "https://payu.herokuapp.com/failure"
    paymentParam.firstName = "Baalak"
    paymentParam.email = "Baalak@gmail.com"
    paymentParam.environment = ENVIRONMENT_TEST
    paymentParam.udf1 = "udf1"
    paymentParam.udf2 = "udf2"
    paymentParam.udf3 = "udf3"
    paymentParam.udf4 = "udf4"
    paymentParam.udf5 = "udf5"
    paymentParam.offerKey = ""              // Set this property if you want to give offer:
    paymentParam.userCredentials = ""
    PUSAHelperClass.generateHash(fromServer: self.paymentParam) { (hashes, errorString) in
      self.hashes = hashes!
      self.paymentParam.hashes = hashes
      self.paymentParam.userCredentials = "gtKFFx:Baalak@gmail.com"
      self.paymentParam.environment = ENVIRONMENT_TEST
      self.callPaymentGateway()
    }
  }
  func callPaymentGateway()  {
    let webServiceResponse :PayUWebServiceResponse = PayUWebServiceResponse()
    webServiceResponse.getPayUPaymentRelatedDetail(forMobileSDK: paymentParam) { (paymentDetail, errString, extraParam) in
      if errString == nil {
        let stryBrd: UIStoryboard = UIStoryboard(name: "PUUIMainStoryBoard", bundle: nil)
        let payOptionVC : PUUIPaymentOptionVC = stryBrd.instantiateViewController(withIdentifier: VC_IDENTIFIER_PAYMENT_OPTION) as! PUUIPaymentOptionVC
        payOptionVC.paymentParam = self.paymentParam
        payOptionVC.paymentRelatedDetail = paymentDetail
        DispatchQueue.main.async {
          NotificationCenter.default.addObserver(self, selector: #selector(self.paymentResponseReceived(notify:)), name: NSNotification.Name(rawValue: kPUUINotiPaymentResponse), object: nil)
          self.navigationController?.pushViewController(payOptionVC, animated: true)
        }
      }
      else{
        print("Failed to proceed for payment : \(String(describing: errString))")
      }
    }
  }
  @objc func paymentResponseReceived(notify:NSNotification) {
    print(notify)
  }
}
 
     
    