code: def test_predict(self):
      y_predicted = self.classifier.predict(self.x_test_diabetes[:4])
      y_expected = np.asarray([69.0, 81.0, 68.0, 68.0])
      np.testing.assert_array_almost_equal(
          y_predicted, y_expected, decimal=1
      )
  
file_path: adversarial-robustness-toolbox/tests/estimators/regression/test_scikitlearn.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import logging
  import unittest
  import numpy
  from sklearn.tree import DecisionTreeRegressor
  from art.estimators.regression.scikitlearn import ScikitlearnDecisionTreeRegressor
  from art.estimators.regression.scikitlearn import ScikitlearnRegressor
  from tests.utils import TestBase, master_seed
label_desc: Use image node_id 3 for calling the TestScikitlearnDecisionTreeRegressor obj's underlying member method code with example usage: obj.test_predict() without return types