digraph {
 rankdir=LR;
 node [shape=Mrecord];
 in [
  label = "{Input source}"
 ];
 out [
  label = "{Output sink}"
 ];
 Transform [
  label = "{{Ryu::Transform|<sink> sink\l|<source> source\l}}"
 ];
 in -> Transform:sink;
 Transform:source -> out;
}