public void visit(SpemVisitor visitor) {
   if (visitor instanceof ModelVisitor) {
     ((ModelVisitor) visitor).visitSynchro(this);
   }
 }
 public void visit(SpemVisitor visitor) {
   if (visitor instanceof ModelVisitor) {
     ((ModelVisitor) visitor).visitDecision(this);
   }
 }
 public void visit(SpemVisitor visitor) {
   if (visitor instanceof ModelVisitor) {
     ((ModelVisitor) visitor).visitFinalPoint(this);
   }
 }
 public void visit(ModelVisitor visitor) {
   visitor.visitTransition(this);
 }