code: def _get_font_afm(self, prop):
      fname = font_manager.findfont(
          prop, fontext="afm", directory=self._afm_font_dir
      )
      return _cached_get_afm_from_fname(fname)
  
imports: from io import BytesIO
  import functools
  from fontTools import subset
  import matplotlib
  from ..None import font_manager, ft2font
  from .._afm import AFM
  from ..backend_bases import RendererBase
label_desc: Use image node_id 7 for calling the RendererPDFPSBase obj's underlying member method code with example usage: obj._get_font_afm(prop) and returns: _cached_get_afm_from_fname