code: def test_clone(self):
      new_classifier = self.classifier.clone_for_refitting()
      new_params = new_classifier.get_params()
      del new_params["model"]
      prev_params = self.classifier.get_params()
      del prev_params["model"]
      assert new_params == prev_params
      assert new_classifier.nb_classes == 3
      new_classifier.fit(
          self.x_test_iris, np.argmax(self.y_test_iris, axis=1)
      )
      assert new_classifier.nb_classes == 3
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import logging
  import unittest
  import xgboost
  import numpy
  from art.estimators.classification.xgboost import XGBoostClassifier
  from tests.utils import TestBase, master_seed
label_desc: Use image node_id 3 for calling the TestXGBoostClassifierPythonAPI obj's underlying member method code with example usage: obj.test_clone() without return types