code: def save_failed_dump(self):
          
  
          # try/except for safety, to not break live spiders
          try:
              # FIXME
              if (self.transport.__class__.__name__ == 'Urllib3Transport'
                      and not getattr(self.transport, '_response', None)):
                  self.doc = None
              else:
                  self.doc = self.transport.prepare_response(self)
              self.copy_request_data()
              self.save_dumps()
          except Exception as ex: # pylint: disable=broad-except
              logger.error('', exc_info=ex)
docs: Save dump of failed request for debugging.
  
          This method is called then fatal network exception is raised.
          The saved dump could be used for debugging the reason of the failure.