code: def batch(self, batch_obj):
          
          if self._connection:
              raise CQLEngineException("Cannot specify the connection on model in batch mode.")
  
          if batch_obj is not None and not isinstance(batch_obj, BatchQuery):
              raise CQLEngineException('batch_obj must be a BatchQuery instance or None')
          clone = copy.deepcopy(self)
          clone._batch = batch_obj
          return clone
docs: Set a batch object to run the query on.
  
          Note: running a select query with a batch object will raise an exception