digraph G {
  /* splines = false; */
  node [ shape = "circle" ];

  subgraph cluster0 {
    c0
    c1
    c2
  }

  subgraph cluster1 {
    n0
    n1
    n2


    n0 -> n1;
    n0 -> n2;
    n1 -> n2;
    n1 -> n0;
    n2 -> n0;
  }


  c0 -> n0;
  c0 -> n2;
  c1 -> n1;
  c1 -> n0;
  c2 -> n0;
  c2 -> n2;
}