code: def test_pickle_roundtrip_pandas():
      result = tm.round_trip_pickle(NA)
      assert result is NA
  
imports: from datetime import date, time, timedelta
  import pickle
  import numpy
  import pytest
  from pandas._libs.missing import NA
  from pandas.core.dtypes.common import is_scalar
  import pandas
  import pandas._testing
label_desc: Use image node_id 27 for calling a global function with example usage: test_pickle_roundtrip_pandas() without return types