--- /dev/null
+digraph "G" {
+subgraph "cluster_0" {
+label="process #1";
+style="filled";
+color="lightgrey";
+node[style="filled",color="white",];
+"a0" ;
+"a1" ;
+"a2" ;
+"a3" ;
+"a0" -> "a1" ;
+"a1" -> "a2" ;
+"a2" -> "a3" ;
+};
+subgraph "cluster_1" {
+label="process #2";
+color="blue";
+node[style="filled",];
+"b0" ;
+"b1" ;
+"b2" ;
+"b3" ;
+"b0" -> "b1" ;
+"b1" -> "b2" ;
+"b2" -> "b3" ;
+};
+"start" [shape="Mdiamond",];
+"end" [shape="Msquare",];
+"start" -> "a0" ;
+"start" -> "b0" ;
+"a1" -> "b3" ;
+"b2" -> "a3" ;
+"a3" -> "a0" ;
+"a3" -> "end" ;
+"b3" -> "end" ;
+}