def validate(self):
     gateway = AfricasTalkingGateway(self.APP_USERNAME, self.API_KEY)
     try:
         # Initiate the request with the transacitonId that was returned
         # by the charge request. If there are no exceptions, that means
         # the transaction was completed successfully
         gateway.bankPaymentCheckoutValidation(
             transactionId_ = 'ATPid_14963d9d924c7f200421a47d4f79e94c',
             otp_           = "1234"
         )
         print 'The transaction was completed successfully'
     except AfricasTalkingGatewayException, e:
         print 'Encountered an error while sending: %s' % str(e)