code: def test_simple_multiclass(self):
      self._train_convert_evaluate_assert()
  
imports: import itertools
  import unittest
  from distutils.version import StrictVersion
  import numpy
  import pandas
  import pytest
  from coremltools._deps import _HAS_SKLEARN, _SKLEARN_VERSION
  from coremltools.models.utils import _is_macos, _macos_version, evaluate_classifier
label_desc: Use image node_id 2 for calling the DecisionTreeMultiClassClassificationBostonHousingScikitNumericTest obj's underlying member method code with example usage: obj.test_simple_multiclass() without return types