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 setup_method(self):
      self.Graph = nx.DiGraph
      # build dict-of-dict-of-dict K3
      ed1, ed2, ed3, ed4, ed5, ed6 = ({}, {}, {}, {}, {}, {})
      self.k3adj = {
          0: {1: ed1, 2: ed2},
          1: {0: ed3, 2: ed4},
          2: {0: ed5, 1: ed6},
      }
      self.k3edges = [(0, 1), (0, 2), (1, 2)]
      self.k3nodes = [0, 1, 2]
      self.K3 = self.Graph()
      self.K3._succ = self.k3adj  # K3._adj is synced with K3._succ
      self.K3._pred = {
          0: {1: ed3, 2: ed5},
          1: {0: ed1, 2: ed6},
          2: {0: ed2, 1: ed4},
      }
      self.K3._node = {}
      self.K3._node[0] = {}
      self.K3._node[1] = {}
      self.K3._node[2] = {}
  
      ed1, ed2 = ({}, {})
      self.P3 = self.Graph()
      self.P3._succ = {0: {1: ed1}, 1: {2: ed2}, 2: {}}
      self.P3._pred = {0: {}, 1: {0: ed1}, 2: {1: ed2}}
      # P3._adj is synced with P3._succ
      self.P3._node = {}
      self.P3._node[0] = {}
      self.P3._node[1] = {}
      self.P3._node[2] = {}
  
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 1 for calling the TestDiGraph obj's underlying member method code with example usage: obj.setup_method() without return types