def _postback(self):
        """Perform PayPal Postback validation."""
        return requests.post(self.get_endpoint(), data=b"cmd=_notify-validate&" + self.query.encode("ascii")).content
def _postback ( self ) : return requests . post ( self . get_endpoint ( ) , data = b"cmd=_notify-validate&" + self . query . encode ( "ascii" ) ) . content
Perform PayPal Postback validation.