code: def test_convex_in_3d():
      canvas = np.zeros((12, 8, 8))
      canvas[3, 4, 2] = 1
      canvas[5, 4, 2] = 1
      canvas[3, 6, 2] = 1
      with pytest.raises(ValueError):
          mahotas.polygon.fill_convexhull(canvas)
  
file_path: mahotas/mahotas/tests/test_polygon.py
imports: import numpy
  import mahotas
  import mahotas.polygon
  from mahotas.polygon import fill_polygon, fill_convexhull
  import pytest
label_desc: Use image node_id 8 for calling a global function with example usage: test_convex_in_3d() without return types