code: def test_predecessor_path(self):
      G = nx.path_graph(4)
      assert nx.predecessor(G, 0) == {0: [], 1: [0], 2: [1], 3: [2]}
      assert nx.predecessor(G, 0, 3) == [2]
  
file_path: networkx/networkx/algorithms/shortest_paths/tests/test_unweighted.py
imports: import pytest
  import networkx
label_desc: Use image node_id 11 for calling the TestUnweightedPath obj's underlying member method code with example usage: obj.test_predecessor_path() without return types