class_docstr: Test the PCA visualizer
class_docstr_tok: ["Test","the","PCA","visualizer"]
code: def test_transform(self, n_components):
      Xprime = PCA(projection=n_components).fit_transform(
          *self.continuous
      )
      assert Xprime.shape == (500, n_components)
  
imports: import sys
  import pytest
  import numpy
  import numpy.testing
  from unittest import mock
  from tests.base import VisualTestCase, IS_WINDOWS_OR_CONDA
  from yellowbrick.features.pca import *
  from yellowbrick.exceptions import YellowbrickError, NotFitted
label_desc: Use image node_id 5 for calling the TestPCA obj's underlying member method code with example usage: obj.test_transform(n_components) without return types