code: def large_collider_graph():
      edge_list = [
          ("A", "B"),
          ("C", "B"),
          ("B", "D"),
          ("D", "E"),
          ("B", "F"),
          ("G", "E"),
      ]
      G = nx.DiGraph(edge_list)
      return G
  
imports: from itertools import combinations
  import pytest
  import networkx
label_desc: Use image node_id 11 for calling a global function with example usage: large_collider_graph() and returns: G