code: def test_normalize_2():
      G = basic_graph()
      G.normalize(0)
      M = G.to_coo_matrix()
      sM = np.array(M.sum(1)).ravel()
      assert (np.abs(sM - 1) < 1.0e-7).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 22 for calling a global function with example usage: test_normalize_2() without return types