code: def test_overwrite_warns(self):
      mean = ps.Series.mean
      try:
          with assert_produces_warning(
              UserWarning, raise_on_extra_warnings=False
          ) as w:
              register_series_accessor("mean")(CustomAccessor)
              s = ps.Series([1, 2])
              assert s.mean.prop == "item"
          msg = str(w[0].message)
          assert "mean" in msg
          assert "CustomAccessor" in msg
          assert "Series" in msg
      finally:
          ps.Series.mean = mean
  
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 8 for calling the ExtensionTestsMixin obj's underlying member method code with example usage: obj.test_overwrite_warns() without return types