class_docstr: Test the PCA visualizer
class_docstr_tok: ["Test","the","PCA","visualizer"]
docstr: Test that appropriate error is raised when transform called without fit.
docstr_tok: ["Test","that","appropriate","error","is","raised","when","transform","called","without","fit","."]
code: def test_transform_without_fit(self):
      """
      Test that appropriate error is raised when transform called without fit.
      """
      oz = PCA(projection=3)
      msg = "instance is not fitted yet, please call fit"
      with pytest.raises(NotFitted, match=msg):
          oz.transform(*self.continuous)
  
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 6 for calling the TestPCA obj's underlying member method code with example usage: obj.test_transform_without_fit() without return types