code: def test_raises_n_classes_error(self):
      model = self.get_dummy_model()
      model.predict = self.get_dummy_func()
  
      with pytest.raises(AssertionError, match="n_classes is required"):
          _check_model(model, None, None)
  
imports: import pandas
  import numpy
  import pytest
  from pdpbox.utils import FeatureInfo, _to_rgba, _check_col, _check_dataset, _make_list, _check_model, _check_classes, _check_memory_limit, _check_frac_to_plot, _calc_n_jobs, _get_string, _expand_params_for_interact, _calc_preds, _check_cluster_params, _check_plot_engine, _check_pdp_interact_plot_type
label_desc: Use image node_id 6 for calling the TestCheckModel obj's underlying member method code with example usage: obj.test_raises_n_classes_error() without return types