final Body body = method.retrieveActiveBody();
CompleteUnitGraph cug = new CompleteUnitGraph(body);
for (Unit aCug : cug) {
assert aCug instanceof Stmt;
Stmt st = (Stmt) aCug;
if (st.containsInvokeExpr()) {
handlePlug(st, body, stateMachine);
queue.addAll(handleInvocation(stateMachine, method, st));
} else if (st instanceof AssignStmt) {
// will not alter control flow, but an unanalyzable rhs
// might pop up