code: def test_string_add_str_num(self):
      pdf = pd.DataFrame(dict(col1=["a"], col2=[1]))
      psdf = ps.from_pandas(pdf)
      with self.assertRaises(TypeError):
          psdf["col1"] + psdf["col2"]
  
imports: import pandas
  import numpy
  import re
  from pyspark import pandas
  from pyspark.testing.pandasutils import PandasOnSparkTestCase
  from pyspark.testing.sqlutils import SQLTestUtils
label_desc: Use image node_id 4 for calling the SeriesStringOpsMixin obj's underlying member method code with example usage: obj.test_string_add_str_num() without return types