code: def test_single_source_dijkstra_path_length(self):
      pl = nx.single_source_dijkstra_path_length
      assert dict(pl(self.MXG4, 0))[2] == 4
      spl = pl(self.MXG4, 0, cutoff=2)
      assert 2 not in spl
  
imports: import pytest
  import networkx
  from networkx.utils import pairwise
label_desc: Use image node_id 9 for calling the TestWeightedPath obj's underlying member method code with example usage: obj.test_single_source_dijkstra_path_length() without return types