class_docstr: Test DecisionBoundariesVisualizer
class_docstr_tok: ["Test","DecisionBoundariesVisualizer"]
docstr: Test correct initialization of the internal state
docstr_tok: ["Test","correct","initialization","of","the","internal","state"]
code: def test_init(self):
      """
      Test correct initialization of the internal state
      """
      model = neighbors.KNeighborsClassifier(3)
      viz = DecisionBoundariesVisualizer(model)
  
      assert viz.step_size == 0.0025
      assert viz.name == "KNeighborsClassifier"
      assert viz.estimator is model
  
      assert not hasattr(viz, "classes_")
      assert viz.features_ is None
      assert viz.markers is not None
      assert viz.scatter_alpha is not None
      assert viz.show_scatter is True
  
      assert viz.Z is None
      assert viz.xx is None
      assert viz.yy is None
      assert viz.class_labels is None
      assert viz.title is None
      assert viz.x is None
      assert viz.y is None
  
imports: import sys
  import pytest
  import numpy
  from unittest import mock
  from tests.base import VisualTestCase
  from yellowbrick.contrib.classifier import *
  from yellowbrick.exceptions import YellowbrickTypeError
  from yellowbrick.exceptions import YellowbrickValueError
  from sklearn import datasets
  from sklearn import neighbors
  from sklearn import naive_bayes
label_desc: Use image node_id 2 for calling the TestDecisionBoundariesVisualizer obj's underlying member method code with example usage: obj.test_init() without return types