code: def test_split(any_string_dtype, method):
      values = Series(
          ["a_b_c", "c_d_e", np.nan, "f_g_h"], dtype=any_string_dtype
      )
  
      result = getattr(values.str, method)("_")
      exp = Series(
          [["a", "b", "c"], ["c", "d", "e"], np.nan, ["f", "g", "h"]]
      )
      exp = _convert_na_value(values, exp)
      tm.assert_series_equal(result, exp)
  
imports: from datetime import datetime
  import re
  import numpy
  import pytest
  import pandas
  from pandas import DataFrame, Index, MultiIndex, Series, _testing
  from pandas.tests.strings import _convert_na_value, object_pyarrow_numpy
label_desc: Use image node_id 1 for calling a global function with example usage: test_split(any_string_dtype, method) without return types