'Add the failed response to the self._last_responses log, and if we got a
lot of failures raise a "ScanMustStopException" subtype.
:param error: Exception object.'

def _log_failed_response(self, error, request):

    reason = get_exception_reason(error)
    reason = (reason or str(error))
    self._last_responses.append(ResponseMeta(False, reason, host=request.get_host()))
    self._log_error_rate()
