code: def test_adjacency():
      G = basic_graph()
      M = G.to_coo_matrix()
      assert (M.diagonal() == 0).all()
      A = M.toarray()
      assert (np.diag(A, 1) != 0).all()
      assert (np.diag(A, -1) != 0).all()
  
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 24 for calling a global function with example usage: test_adjacency() without return types