code: def test_nonzero_single_element(self):
      # allow single item via bool method
      msg_warn = (
          "Series.bool is now deprecated and will be removed "
          "in future version of pandas"
      )
      ser = Series([True])
      ser1 = Series([False])
      with tm.assert_produces_warning(FutureWarning, match=msg_warn):
          assert ser.bool()
      with tm.assert_produces_warning(FutureWarning, match=msg_warn):
          assert not ser1.bool()
  
file_path: pandas/pandas/tests/generic/test_series.py
imports: from operator import methodcaller
  import numpy
  import pytest
  import pandas
  from pandas import MultiIndex, Series, date_range
  import pandas._testing
label_desc: Use image node_id 4 for calling the TestSeries obj's underlying member method code with example usage: obj.test_nonzero_single_element() without return types