code: def test_predict_new_category(self):
      # Arrange
      new_test = copy.copy(self.dtest)
      # change 'r' cap-color  into a new color 'z'
      new_test["cap-color"] = new_test["cap-color"].apply(
          lambda x: "z" if x == "r" else x
      )
  
      # Act
      y1 = self.model.predict(new_test)
      y2 = self.model.predict(list(new_test))
  
      # Assert
      self.assertEqual(list(y1), list(y2))
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import unittest
  import turicreate
  import math
  import uuid
  import random
  import copy
  from turicreate.toolkits import evaluation
  from turicreate.toolkits._main import ToolkitError
  import shutil
  import numpy
  from array import array
  import os
label_desc: Use image node_id 14 for calling the DecisionTreeRegressionTest obj's underlying member method code with example usage: obj.test_predict_new_category() without return types