code: def _expand_cmdclass(self, package_dir: Mapping[str, str]):
      root_dir = self.root_dir
      cmdclass = partial(
          _expand.cmdclass, package_dir=package_dir, root_dir=root_dir
      )
      self._process_field(self.setuptools_cfg, "cmdclass", cmdclass)
  
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 8 for calling the _ConfigExpander obj's underlying member method code with example usage: obj._expand_cmdclass(package_dir) without return types