code: def test_to_coo_matrix():
      """Test the generation of a sparse matrix as output"""
      a = (np.random.randn(5, 5) > 0.8).astype(np.float64)
      wg = wgraph_from_adjacency(a)
      b = wg.to_coo_matrix().todense()
      assert_array_equal(a, b)
  
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 45 for calling a global function with example usage: test_to_coo_matrix() without return types