digraph {
  pad=0.5; bgcolor="lightgrey"; nodesep=1;
  node [shape="box"; style="filled";  fillcolor="cyan";  ];
  edge [labelfontsize=10; minlen=2; labeldistance=3 ];
  DOOR_CLOSED -> DOOR_OPEN [taillabel="EVT_OPEN"];
  DOOR_OPEN -> BEEPING [taillabel="EVT_TICK \n&& counter==0"];
  BEEPING -> DOOR_CLOSED [taillabel="EVT_CLOSE"];
  DOOR_OPEN -> DOOR_CLOSED  [taillabel="EVT_CLOSE"];
  {rank=same; DOOR_OPEN BEEPING}
}

