code: def test_findall(any_string_dtype):
      ser = Series(
          ["fooBAD__barBAD", np.nan, "foo", "BAD"],
          dtype=any_string_dtype,
      )
      result = ser.str.findall("BAD[_]*")
      expected = Series([["BAD__", "BAD"], np.nan, [], ["BAD"]])
      expected = _convert_na_value(ser, expected)
      tm.assert_series_equal(result, expected)
  
imports: from datetime import datetime
  import re
  import numpy
  import pytest
  from pandas.errors import PerformanceWarning
  import pandas.util._test_decorators
  import pandas
  from pandas import Series, _testing
  from pandas.tests.strings import _convert_na_value, object_pyarrow_numpy
label_desc: Use image node_id 40 for calling a global function with example usage: test_findall(any_string_dtype) without return types