code: def test_bfs_edges(self):
      edges = nx.bfs_edges(self.G, source=0)
      assert list(edges) == [(0, 1), (1, 2), (1, 3), (2, 4)]
  
imports: from functools import partial
  import pytest
  import networkx
label_desc: Use image node_id 5 for calling the TestBFS obj's underlying member method code with example usage: obj.test_bfs_edges() without return types