class_docstr: Unit test class for testing scikit-learn converter and running both models
code: def test_boston_housing_simple_regression(self):
      self._train_convert_evaluate_assert(max_depth=20)
  
file_path: coremltools/coremltools/test/xgboost_tests/test_decision_tree_regression_numeric.py
imports: import itertools
  import unittest
  from distutils.version import StrictVersion
  import pandas
  import pytest
  from coremltools._deps import _HAS_SKLEARN, _SKLEARN_VERSION
  from coremltools.models.utils import _is_macos, _macos_version, evaluate_regressor
label_desc: Use image node_id 4 for calling the DecisionTreeRegressorBostonHousingScikitNumericTest obj's underlying member method code with example usage: obj.test_boston_housing_simple_regression() without return types