code: def test_moments_normalized_spacing(anisotropic):
      image = np.zeros((20, 20), dtype=np.double)
      image[13:17, 13:17] = 1
  
      if not anisotropic:
          spacing1 = (1, 1)
          spacing2 = (3, 3)
      else:
          spacing1 = (1, 2)
          spacing2 = (2, 4)
  
      mu = moments_central(image, spacing=spacing1)
      nu = moments_normalized(mu, spacing=spacing1)
  
      mu2 = moments_central(image, spacing=spacing2)
      nu2 = moments_normalized(mu2, spacing=spacing2)
  
      # result should be invariant to absolute scale of spacing
      compare_moments(nu, nu2)
  
imports: import itertools
  import numpy
  import pytest
  from scipy import ndimage
  from skimage import draw
  from skimage._shared import testing
  from skimage._shared.testing import assert_allclose, assert_almost_equal, assert_equal
  from skimage._shared.utils import _supported_float_type
  from skimage.measure import centroid, inertia_tensor, inertia_tensor_eigvals, moments, moments_central, moments_coords, moments_coords_central, moments_hu, moments_normalized
label_desc: Use image node_id 8 for calling a global function with example usage: test_moments_normalized_spacing(anisotropic) without return types