def _check_response_for_request_errors(self):
        """
        Checks the response to see if there were any errors specific to
        this WSDL.
        """
        if self.response.HighestSeverity == "ERROR":  # pragma: no cover
            for notification in self.response.Notifications:
                if notification.Severity == "ERROR":
                    if "Invalid tracking number" in notification.Message:
                        raise FedexInvalidTrackingNumber(
                                notification.Code, notification.Message)
                    else:
                        raise FedexError(notification.Code, notification.Message)