code: def setUpClass(self):
      from sklearn.datasets import load_boston
      import numpy as np
  
      # Load data and train model
      scikit_data = load_boston()
      num_classes = 3
      self.X = scikit_data.data.astype("f").astype(
          "d"
      )  ## scikit-learn downcasts data
      t = scikit_data.target
      target = (
          np.digitize(t, np.histogram(t, bins=num_classes - 1)[1]) - 1
      )
  
      # Save the data and the model
      self.scikit_data = scikit_data
      self.target = target
      self.feature_names = scikit_data.feature_names
      self.output_name = "target"
  
imports: import os
  import itertools
  import pandas
  import unittest
  from coremltools._deps import _HAS_SKLEARN
  from coremltools.models.utils import evaluate_classifier, _macos_version, _is_macos
  import pytest
label_desc: Use image node_id 1 for calling the DecisionTreeMultiClassClassificationBostonHousingScikitNumericTest obj's underlying member method code with example usage: obj.setUpClass() without return types