void drawing_data_request_begin(EventsRequest *events_request,
LttvTracesetState *tss);
void drawing_chunk_begin(EventsRequest *events_request, LttvTracesetState *tss);
void drawing_data_request_begin(EventsRequest *events_request,
LttvTracesetState *tss);
void drawing_chunk_begin(EventsRequest *events_request, LttvTracesetState *tss);