code: def _expand_data_files(self):
      data_files = partial(
          _expand.canonic_data_files, root_dir=self.root_dir
      )
      self._process_field(self.setuptools_cfg, "data-files", data_files)
  
imports: import logging
  import os
  from contextlib import contextmanager
  from functools import partial
  from typing import TYPE_CHECKING, Callable, Dict, Mapping, Optional, Set, Union
  from ..errors import FileError, InvalidConfigError
  from ..warnings import SetuptoolsWarning
  from .None import expand
  from ._apply_pyprojecttoml import _PREVIOUSLY_DEFINED, _MissingDynamic
  from ._apply_pyprojecttoml import apply
label_desc: Use image node_id 7 for calling the _ConfigExpander obj's underlying member method code with example usage: obj._expand_data_files() without return types