code: def test_structure_tensor_eigenvalues_3d():
      image = np.pad(cube(9), 5, mode="constant") * 1000
      boundary = (
          np.pad(cube(9), 5, mode="constant")
          - np.pad(cube(7), 6, mode="constant")
      ).astype(bool)
      A_elems = structure_tensor(image, sigma=0.1)
      e0, e1, e2 = structure_tensor_eigenvalues(A_elems)
      # e0 should detect facets
      assert np.all(e0[boundary] != 0)
  
imports: import numpy
  import pytest
  from numpy.testing import assert_almost_equal, assert_array_equal, assert_equal
  from skimage import data, draw, img_as_float
  from skimage._shared._warnings import expected_warnings
  from skimage._shared.testing import run_in_parallel
  from skimage._shared.utils import _supported_float_type
  from skimage.color import rgb2gray
  from skimage.feature import corner_fast, corner_foerstner, corner_harris, corner_kitchen_rosenfeld, corner_moravec, corner_orientations, corner_peaks, corner_shi_tomasi, corner_subpix, hessian_matrix, hessian_matrix_det, hessian_matrix_eigvals, peak_local_max, shape_index, structure_tensor, structure_tensor_eigenvalues
  from skimage.morphology import cube, octagon
label_desc: Use image node_id 12 for calling a global function with example usage: test_structure_tensor_eigenvalues_3d() without return types