code: def setUp(self):
      self.model = lambda: None
      self.model.predict = types.MethodType(self.predict, self.model)
      self.preprocessing = ce.OneHotEncoder(cols=["Onehot1", "Onehot2"])
  
      self.test_backend = TestBackend(
          model=self.model, preprocessing=self.preprocessing
      )
  
imports: import unittest
  from unittest.mock import patch
  import types
  import numpy
  import pandas
  import category_encoders
  from sklearn.ensemble import RandomForestRegressor, RandomForestClassifier
  from pandas.testing import assert_frame_equal, assert_series_equal
  from shapash.backend.base_backend import BaseBackend, _needs_preprocessing
  from shapash.explainer.smart_state import SmartState
label_desc: Use image node_id 2 for calling the TestBaseBackend obj's underlying member method code with example usage: obj.setUp() without return types