code: def test_forest_regressor(self):
      for ForestRegressor in (
          RandomForestRegressor,
          ExtraTreesRegressor,
      ):
          X = self.boston.data
          Y = self.boston.target
          testX = X[int(len(X) / 2) :]
  
          # Predict for decision tree
          dt = ForestRegressor(n_estimators=10)
          dt.fit(X[: int(len(X) / 2)], Y[: int(len(X) / 2)])
  
          base_prediction = dt.predict(testX)
          pred, bias, contrib = treeinterpreter.predict(dt, testX)
          self.assertTrue(np.allclose(base_prediction, pred))
          self.assertTrue(
              np.allclose(pred, bias + np.sum(contrib, axis=1))
          )
  
file_path: treeinterpreter/tests/test_treeinterpreter.py
imports: import numpy
  import unittest
  from sklearn.datasets import load_boston, load_iris
  from sklearn.ensemble import RandomForestRegressor, RandomForestClassifier, ExtraTreesClassifier, ExtraTreesRegressor
  from sklearn.tree import DecisionTreeClassifier, DecisionTreeRegressor, ExtraTreeClassifier, ExtraTreeRegressor
  from treeinterpreter import treeinterpreter
label_desc: Use image node_id 4 for calling the TestTreeinterpreter obj's underlying member method code with example usage: obj.test_forest_regressor() without return types