code: def _find_missing_edge(G):
      """Given a non-complete graph G, returns a missing edge."""
      nodes = set(G)
      for u in G:
          missing = nodes - set(list(G[u].keys()) + [u])
          if missing:
              return (u, missing.pop())
  
file_path: networkx/networkx/algorithms/chordal.py
imports: import sys
  import networkx
  from networkx.algorithms.components import connected_components
  from networkx.utils import arbitrary_element, not_implemented_for
label_desc: Use image node_id 6 for calling a global function with example usage: _find_missing_edge(G) and returns: u,  missing