-// template <class AnyActivity> class DependencyGuard {
-// public:
-// static bool activity_start_vetoer(AnyActivity* a) { return not a->has_dependencies(); }
-// static void on_activity_done(AnyActivity* a);
-//// {
-//// while (a->has_successors()) {
-//// AnyActivity* b = a->get_successor();
-//// b->remove_dependency_on(a);
-//// if (not b->has_dependencies()) {
-//// XBT_INFO("Activity is done and a successor can start");
-//// b->vetoable_start();
-//// }
-//// a->remove_successor();
-//// }
-//// }
-//};
-