code: def test_shortest_path_length(self):
      assert nx.shortest_path_length(self.cycle, 0, 3) == 3
      assert nx.shortest_path_length(self.grid, 1, 12) == 5
      assert nx.shortest_path_length(self.directed_cycle, 0, 4) == 4
      # now with weights
      assert nx.shortest_path_length(self.cycle, 0, 3, weight=True) == 3
      assert nx.shortest_path_length(self.grid, 1, 12, weight=True) == 5
      assert (
          nx.shortest_path_length(
              self.directed_cycle, 0, 4, weight=True
          )
          == 4
      )
  
file_path: networkx/networkx/algorithms/shortest_paths/tests/test_unweighted.py
imports: import pytest
  import networkx
label_desc: Use image node_id 4 for calling the TestUnweightedPath obj's underlying member method code with example usage: obj.test_shortest_path_length() without return types