code: def find_alternating_4_cycle(G):
      """
      Returns False if there aren't any alternating 4 cycles.
      Otherwise returns the cycle as [a,b,c,d] where (a,b)
      and (c,d) are edges and (a,c) and (b,d) are not.
      """
      for u, v in G.edges():
          for w in G.nodes():
              if not G.has_edge(u, w) and u != w:
                  for x in G.neighbors(w):
                      if not G.has_edge(v, x) and v != x:
                          return [u, v, w, x]
      return False
  
imports: from math import sqrt
  import networkx
  from networkx.utils import py_random_state
label_desc: Use image node_id 9 for calling a global function with example usage: find_alternating_4_cycle(G) and returns: False, list