code: def test_voronoi2():
      """test voronoi labelling with one seed"""
      a = np.array([0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6])
      b = np.array([1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 0, 0, 1])
      d = np.array([1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2])
      edges = np.vstack((a, b)).T
      G = WeightedGraph(7, edges, d)
      G.symmeterize()
      seed = np.array([0])
      label = G.voronoi_labelling(seed)
      assert label[4] == 0
  
imports: import numpy
  import numpy.random
  from numpy.testing import assert_almost_equal, assert_array_almost_equal, assert_array_equal
  from ..graph import WeightedGraph, complete_graph, concatenate_graphs, eps_nn, knn, mst, wgraph_from_3d_grid, wgraph_from_adjacency, wgraph_from_coo_matrix
label_desc: Use image node_id 36 for calling a global function with example usage: test_voronoi2() without return types