code: def test_setup(self):
      self.assertEqual("item", self.accessor.item)
  
imports: import contextlib
  import numpy
  import pandas
  from pyspark import pandas
  from pyspark.testing.pandasutils import assert_produces_warning, ComparisonTestBase
  from pyspark.pandas.extensions import register_dataframe_accessor, register_series_accessor, register_index_accessor
label_desc: Use image node_id 3 for calling the ExtensionTestsMixin obj's underlying member method code with example usage: obj.test_setup() without return types