class_docstr: Test DataVisualizer base class
class_docstr_tok: ["Test","DataVisualizer","base","class"]
docstr: Test color assignment for single target type
code: def test_get_colors_single(self, color, expected):
      """
      Test color assignment for single target type
      """
      X, y = self.discrete
      oz = DataVisualizer(colors=color).fit(X)
      assert oz.get_target_color_type() == TargetType.SINGLE
  
      # Test default colors
      colors = oz.get_colors(y)
      assert len(colors) == len(y)
      assert np.unique(colors) == expected
  
imports: import pytest
  import numpy
  import numpy.testing
  from tests.fixtures import Dataset
  from yellowbrick.base import Visualizer
  from yellowbrick.features.base import *
  from sklearn.base import BaseEstimator, TransformerMixin
  from sklearn.datasets import make_classification, make_regression
  from unittest.mock import Mock
label_desc: Use image node_id 13 for calling the TestDataVisualizer obj's underlying member method code with example usage: obj.test_get_colors_single(color, expected) without return types