code: def test_get_all():
      ppdb = PandasMmcif()
      ppdb.read_mmcif(TESTDATA_FILENAME)
      for i in ["c-alpha", "hydrogen", "main chain"]:
          ppdb.get(i)
  
imports: import os
  from urllib.error import HTTPError
  from urllib.request import urlopen
  from pathlib import Path
  import numpy
  import pandas
  from biopandas.mmcif import PandasMmcif
  from biopandas.pdb import PandasPdb
  from biopandas.testutils import assert_raises
  from nose.tools import raises
  from pandas.testing import assert_frame_equal
label_desc: Use image node_id 11 for calling a global function with example usage: test_get_all() without return types