Create calculation placeholder in item's modified attribute dict
(self, key)
| 296 | key in self.__modified or key in self.__intermediary |
| 297 | |
| 298 | def __placehold(self, key): |
| 299 | """Create calculation placeholder in item's modified attribute dict""" |
| 300 | self.__modified[key] = self.CalculationPlaceholder |
| 301 | |
| 302 | def __len__(self): |
| 303 | keys = set() |