code: def test_gvoronoi():
      labeled = np.zeros((128, 128))
      labeled[0, 0] = 1
      labeled[-1, -1] = 2
      regions = gvoronoi(labeled)
      Y, X = np.where(regions == 1)
      assert np.all(Y + X < 128)
  
imports: import numpy
  from mahotas.segmentation import gvoronoi
label_desc: Use image node_id 3 for calling a global function with example usage: test_gvoronoi() without return types