code: def test_plot(self):
      try:
          import matplotlib.pyplot  # noqa
      except ImportError:
          import nose
  
          raise nose.SkipTest()
  
      y_true = [
          "rabbit",
          "cat",
          "rabbit",
          "rabbit",
          "cat",
          "dog",
          "dog",
          "rabbit",
          "rabbit",
          "cat",
          "dog",
          "rabbit",
      ]
      y_pred = [
          "cat",
          "cat",
          "rabbit",
          "dog",
          "cat",
          "rabbit",
          "dog",
          "cat",
          "rabbit",
          "cat",
          "rabbit",
          "rabbit",
      ]
  
      cm = ConfusionMatrix(y_true, y_pred)
  
      # check plot works
      cm.plot()
      cm.plot(backend="seaborn")
  
      with pytest.raises(ValueError):
          cm.plot(backend="xxx")
  
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 17 for calling the TestConfusionMatrix obj's underlying member method code with example usage: obj.test_plot() without return types