code: def test_reverse_hashable(self):
      class Foo:
          pass
  
      x = Foo()
      y = Foo()
      G = nx.DiGraph()
      G.add_edge(x, y)
      assert nodes_equal(G.nodes(), G.reverse().nodes())
      assert [(y, x)] == list(G.reverse().edges())
  
imports: import pytest
  import networkx
  from networkx.utils import nodes_equal
  from .test_graph import BaseAttrGraphTester, BaseGraphTester
  from .test_graph import TestEdgeSubgraph
  from .test_graph import TestGraph
label_desc: Use image node_id 18 for calling the BaseDiGraphTester obj's underlying member method code with example usage: obj.test_reverse_hashable() without return types