code: def test_dijkstra_predecessor2(self):
      # 4-cycle
      G = nx.Graph([(0, 1), (1, 2), (2, 3), (3, 0)])
      pred, dist = nx.dijkstra_predecessor_and_distance(G, (0))
      assert pred[0] == []
      assert pred[1] == [0]
      assert pred[2] in [[1, 3], [3, 1]]
      assert pred[3] == [0]
      assert dist == {0: 0, 1: 1, 2: 2, 3: 1}
  
imports: import pytest
  import networkx
  from networkx.utils import pairwise
label_desc: Use image node_id 7 for calling the TestWeightedPath obj's underlying member method code with example usage: obj.test_dijkstra_predecessor2() without return types