code: def _initialize_parameters(
      G1, G2, G2_degree, node_label=None, default_label=-1
  ):
      """Initializes all the necessary parameters for VF2++
  
      Parameters
      ----------
      G1,G2: NetworkX Graph or MultiGraph instances.
          The two graphs to check for isomorphism or monomorphism
  
      G1_labels,G2_labels: dict
          The label of every node in G1 and G2 respectively
  
      Returns
      -------
      graph_params: namedtuple
          Contains all the Graph-related parameters:
  
          G1,G2
          G1_labels,G2_labels: dict
  
      state_params: namedtuple
          Contains all the State-related parameters:
  
          mapping: dict
              The mapping as extended so far. Maps nodes of G1 to nodes of G2
  
          reverse_mapping: dict
              The reverse mapping as extended so far. Maps nodes from G2 to nodes of G1. It's basically "mapping" reversed
  
          T1, T2: set
              Ti contains uncovered neighbors of covered nodes from Gi, i.e. nodes that are not in the mapping, but are
              neighbors of nodes that are.
  
          T1_out, T2_out: set
              Ti_out contains all the nodes from Gi, that are neither in the mapping nor in Ti
      """
      G1_labels = dict(G1.nodes(data=node_label, default=default_label))
      G2_labels = dict(G2.nodes(data=node_label, default=default_label))
  
      graph_params = _GraphParameters(
          G1,
          G2,
          G1_labels,
          G2_labels,
          nx.utils.groups(G1_labels),
          nx.utils.groups(G2_labels),
          nx.utils.groups(G2_degree),
      )
  
      T1, T1_in = set(), set()
      T2, T2_in = set(), set()
      if G1.is_directed():
          T1_tilde, T1_tilde_in = (
              set(G1.nodes()),
              set(),
          )  # todo: do we need Ti_tilde_in? What nodes does it have?
          T2_tilde, T2_tilde_in = set(G2.nodes()), set()
      else:
          T1_tilde, T1_tilde_in = set(G1.nodes()), set()
          T2_tilde, T2_tilde_in = set(G2.nodes()), set()
  
      state_params = _StateParameters(
          {},
          {},
          T1,
          T1_in,
          T1_tilde,
          T1_tilde_in,
          T2,
          T2_in,
          T2_tilde,
          T2_tilde_in,
      )
  
      return graph_params, state_params
  
file_path: networkx/networkx/algorithms/isomorphism/vf2pp.py
imports: import collections
  import networkx
label_desc: Use image node_id 5 for calling a global function with example usage: _initialize_parameters(G1, G2, G2_degree, node_label, default_label) and returns: graph_params,  state_params