code: def combined_loader(self) -> CombinedLoader:
      if self._combined_loader is None:
          raise MisconfigurationException(
              f"`{self.__class__.__name__}` should have been `setup` with a `CombinedLoader`."
          )
      return self._combined_loader
  
imports: from typing import Any, Iterator, List, Optional
  from typing_extensions import override
  from lightning.fabric.utilities.data import sized_len
  from lightning.pytorch.utilities.combined_loader import _ITERATOR_RETURN, CombinedLoader
  from lightning.pytorch.utilities.exceptions import MisconfigurationException
label_desc: Use image node_id 2 for calling the _DataFetcher obj's underlying member method code with example usage: obj.combined_loader() and returns: self