We should define how to get ready for the fetching.
(self, *args, **kwargs)
| 41 | """ |
| 42 | |
| 43 | def __init__(self, *args, **kwargs): # pylint: disable=W0246 |
| 44 | """ |
| 45 | We should define how to get ready for the fetching. |
| 46 | """ |
| 47 | super().__init__(*args, **kwargs) |
| 48 | |
| 49 | CS_ALL = "__all" # return all columns with single-level index column |
| 50 | CS_RAW = "__raw" # return raw data with multi-level index column |