code: def test_power():
      image = numpy.ones((20, 10))
      images_and_masks = [(image.copy(), None) for i in range(9)]
      for i, (img, _) in enumerate(images_and_masks):
          img[5, 5] *= numpy.sin(2 * numpy.pi * float(i) / 9.0)
      image_out = run_image_set(
          cellprofiler.modules.makeprojection.P_POWER,
          images_and_masks,
          frequency=9,
      )
      i, j = numpy.mgrid[: image.shape[0], : image.shape[1]]
      numpy.testing.assert_almost_equal(
          image_out.pixel_data[(i != 5) & (j != 5)], 0
      )
      assert image_out.pixel_data[5, 5] > 1
  
imports: import numpy
  import six.moves
  import cellprofiler_core.image
  import cellprofiler_core.measurement
  import cellprofiler.modules.makeprojection
  import cellprofiler_core.object
  import cellprofiler_core.pipeline
  import cellprofiler_core.workspace
  import tests.frontend.modules
label_desc: Use image node_id 11 for calling a global function with example usage: test_power() without return types