code: def test_get_familyname_guessed():
      fh = BytesIO(AFM_TEST_DATA)
      font = _afm.AFM(fh)
      del font._header[
          b"FamilyName"
      ]  # remove FamilyName, so we have to guess
      assert font.get_familyname() == "My Font"
  
file_path: matplotlib/lib/matplotlib/tests/test_afm.py
imports: from io import BytesIO
  import pytest
  import logging
  from matplotlib import _afm
  from matplotlib import font_manager
label_desc: Use image node_id 4 for calling a global function with example usage: test_get_familyname_guessed() without return types