virtual void pre_move_processing();
virtual void post_move_processing();
virtual void acknowledge_element(Staff_elem_info info);
virtual void pre_move_processing();
virtual void post_move_processing();
virtual void acknowledge_element(Staff_elem_info info);
virtual void process_requests();
virtual ~Register_group_register();
virtual void add(Request_register* reg_p);
virtual void process_requests();
virtual ~Register_group_register();
virtual void add(Request_register* reg_p);