+struct hw_event *hw_event_queue_schedule_tracef
+(struct hw *me,
+ signed64 delta_time,
+ hw_event_callback *handler,
+ void *data,
+ const char *fmt,
+ ...) __attribute__ ((format (printf, 5, 6)));
+
+struct hw_event *hw_event_queue_schedule_vtracef
+(struct hw *me,
+ signed64 delta_time,
+ hw_event_callback *handler,
+ void *data,
+ const char *fmt,
+ va_list ap);
+
+