+ void sleep(Thread *t);
+ void wake(Thread *t);
+ Thread * next_thread(Thread *t);
+ Thread * get_current_thread() const;
+ void print() const;
+ enabled_type_t * get_enabled() { return enabled; };
+ void remove_sleep(Thread *t);
+ void add_sleep(Thread *t);
+ enabled_type_t get_enabled(Thread *t);
+ void update_sleep_set(Node *n);
+ bool is_enabled(Thread *t) const;