code: def test_isin(self):
      df = tm.SubclassedDataFrame(
          {"num_legs": [2, 4], "num_wings": [2, 0]},
          index=["falcon", "dog"],
      )
      result = df.isin([0, 2])
      assert isinstance(result, tm.SubclassedDataFrame)
  
imports: import numpy
  import pytest
  import pandas
  from pandas import DataFrame, Index, MultiIndex, Series
  import pandas._testing
label_desc: Use image node_id 20 for calling the TestDataFrameSubclassing obj's underlying member method code with example usage: obj.test_isin() without return types