code: def test_boston_housing_simple_decision_tree_regression(self):
      self._train_convert_evaluate_assert(n_estimators=1)
  
imports: import unittest
  import pandas
  import itertools
  import pytest
  from coremltools._deps import _HAS_SKLEARN, _HAS_XGBOOST
  from coremltools.models.utils import evaluate_regressor, _macos_version, _is_macos
label_desc: Use image node_id 6 for calling the XGboostRegressorBostonHousingNumericTest obj's underlying member method code with example usage: obj.test_boston_housing_simple_decision_tree_regression() without return types