class_docstr: Tests specific to dict-of-dict-of-dict digraph data structure
class_docstr_tok: ["Tests","specific","to","dict-of-dict-of-dict","digraph","data","structure"]
code: def test_remove_edge(self):
      G = self.K3.copy()
      G.remove_edge(0, 1)
      assert G.succ == {
          0: {2: {}},
          1: {0: {}, 2: {}},
          2: {0: {}, 1: {}},
      }
      assert G.pred == {
          0: {1: {}, 2: {}},
          1: {2: {}},
          2: {0: {}, 1: {}},
      }
      with pytest.raises(nx.NetworkXError):
          G.remove_edge(-1, 0)
  
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 5 for calling the TestDiGraph obj's underlying member method code with example usage: obj.test_remove_edge() without return types