digraph stencil3D {
  rankdir=LR;
  init  [label="init"]
  stencil [label="stencil", fillcolor=white;]
  check [label="check", shape=diamond, style=filled, fillcolor=aquamarine];
  init  -> stencil;
  stencil -> check;
  check -> stencil [label="0", style=dashed, constraint=false];
}

