class_docstr: FeatureCorrelation visualizer
class_docstr_tok: ["FeatureCorrelation","visualizer"]
docstr: Test selecting feature by index
docstr_tok: ["Test","selecting","feature","by","index"]
code: def test_feature_correlation_select_feature_by_index(self):
      """
      Test selecting feature by index
      """
      viz = FeatureCorrelation(feature_index=[0, 2, 3])
      viz.fit(self.X, self.y)
  
      assert viz.scores_.shape[0] == 3
  
imports: import sys
  import pytest
  import numpy
  import numpy.testing
  from yellowbrick.target import FeatureCorrelation, feature_correlation
  from yellowbrick.exceptions import YellowbrickValueError, YellowbrickWarning
  from sklearn import datasets
  from tests.base import VisualTestCase
label_desc: Use image node_id 9 for calling the TestFeatureCorrelationVisualizer obj's underlying member method code with example usage: obj.test_feature_correlation_select_feature_by_index() without return types