guint lttv_process_traceset_seek_n_backward(LttvTracesetContext *self,
guint n, LttTime first_offset,
seek_time_fct time_seeker,
guint lttv_process_traceset_seek_n_backward(LttvTracesetContext *self,
guint n, LttTime first_offset,
seek_time_fct time_seeker,