def METHOD_NAME():
    ren, passes = make_passes()
    assert not passes._blur_passes
    blur_pass = passes.add_blur_pass()
    assert isinstance(blur_pass, _vtk.vtkGaussianBlurPass)
    assert len(passes._blur_passes) == 1
    passes.remove_blur_pass()
    assert not passes._blur_passes
    # double pass should work
    blur_pass = passes.add_blur_pass()
    blur_pass = passes.add_blur_pass()
    assert len(passes._blur_passes) == 2