code: def pappus_graph():
      """
      Returns the Pappus graph.
  
      The Pappus graph is a cubic symmetric distance-regular graph with 18 nodes
      and 27 edges. It is Hamiltonian and can be represented in LCF notation as
      [5,7,-7,7,-7,-5]^3 [1]_.
  
      Returns
      -------
      G : networkx Graph
          Pappus graph
  
      References
      ----------
      .. [1] https://en.wikipedia.org/wiki/Pappus_graph
      """
      G = LCF_graph(18, [5, 7, -7, 7, -7, -5], 3)
      G.name = "Pappus Graph"
      return G
  
imports: from functools import wraps
  import networkx
  from networkx.exception import NetworkXError
  from networkx.generators.classic import complete_graph, cycle_graph, empty_graph, path_graph
label_desc: Use image node_id 18 for calling a global function with example usage: pappus_graph() and returns: G