class_docstr: Test ConfusionMatrix visualizer
class_docstr_tok: ["Test","ConfusionMatrix","visualizer"]
docstr: Assert that only classifiers can be used with the visualizer.
docstr_tok: ["Assert","that","only","classifiers","can","be","used","with","the","visualizer","."]
code: def test_isclassifier(self):
      """
      Assert that only classifiers can be used with the visualizer.
      """
      model = PassiveAggressiveRegressor()
      message = (
          "This estimator is not a classifier; "
          "try a regression or clustering score visualizer instead!"
      )
  
      with pytest.raises(yb.exceptions.YellowbrickError, match=message):
          ConfusionMatrix(model)
  
imports: import sys
  import pytest
  import yellowbrick
  import numpy.testing
  import matplotlib.pyplot
  from yellowbrick.exceptions import ModelError
  from yellowbrick.datasets import load_occupancy
  from yellowbrick.classifier.confusion_matrix import *
  from unittest.mock import patch
  from tests.fixtures import Dataset, Split
  from tests.base import IS_WINDOWS_OR_CONDA, VisualTestCase
  from sklearn.svm import SVC
  from sklearn.naive_bayes import GaussianNB
  from sklearn.preprocessing import LabelEncoder
  from sklearn.tree import DecisionTreeClassifier
  from sklearn.linear_model import LogisticRegression
  from sklearn.linear_model import PassiveAggressiveRegressor
  from sklearn.model_selection import train_test_split
  from sklearn.datasets import load_digits, make_classification
  from sklearn.preprocessing import MinMaxScaler
  from sklearn.pipeline import Pipeline
label_desc: Use image node_id 11 for calling the TestConfusionMatrix obj's underlying member method code with example usage: obj.test_isclassifier() without return types