code: def test_wisconsin():
      transform = dgl.AddSelfLoop(allow_duplicate=True)
  
      g = dgl.data.WisconsinDataset(force_reload=True)[0]
      assert g.num_nodes() == 251
      assert g.num_edges() == 515
      g2 = dgl.data.WisconsinDataset(
          force_reload=True, transform=transform
      )[0]
      assert g2.num_edges() - g.num_edges() == g.num_nodes()
  
file_path: dgl/tests/python/common/data/test_geom_gcn.py
imports: import unittest
  import backend
  import dgl
label_desc: Use image node_id 5 for calling a global function with example usage: test_wisconsin() without return types