code: def test_pandas_confusion_cm_empty_column(self):
      y_true = [2, 0, 2, 2, 0, 1]
      y_pred = [0, 0, 2, 2, 0, 2]
      # cm = LabeledConfusionMatrix(y_true, y_pred)
      cm = ConfusionMatrix(
          y_true, y_pred, labels=["ant", "bird", "cat"]
      )
      assert isinstance(
          cm, pdml.confusion_matrix.LabeledConfusionMatrix
      )
  
      cm = ConfusionMatrix(y_true, y_pred)
      assert isinstance(
          cm, pdml.confusion_matrix.LabeledConfusionMatrix
      )
  
      print("Confusion matrix:\n%s" % cm)
      asserts(y_true, y_pred, cm)
  
imports: import pytest
  import matplotlib
  import numpy
  import pandas
  import pandas_ml.util.testing
  import pandas_ml
  from pandas_ml import ConfusionMatrix
  from collections import OrderedDict
label_desc: Use image node_id 4 for calling the TestConfusionMatrix obj's underlying member method code with example usage: obj.test_pandas_confusion_cm_empty_column() without return types