code: def test_out_argument():
      for func in (
          isotropic.isotropic_erosion,
          isotropic.isotropic_dilation,
      ):
          radius = 3
          img = np.ones((10, 10))
          out = np.zeros_like(img)
          out_saved = out.copy()
          func(img, radius, out=out)
          assert np.any(out != out_saved)
          assert_array_equal(out, func(img, radius))
  
file_path: scikit-image/skimage/morphology/tests/test_isotropic.py
imports: import numpy
  from numpy.testing import assert_array_equal
  from skimage import color, data, morphology
  from skimage.morphology import binary, isotropic
  from skimage.util import img_as_bool
label_desc: Use image node_id 9 for calling a global function with example usage: test_out_argument() without return types