_ti_find_extra
if (_ti_find_extra(tic, &tic->extras, id) != NULL)
const char *_ti_find_extra(TIC *, TBUF *, const char *);
while ((cap = _ti_find_extra(rtic, &rtic->extras, "use"))
if (_ti_find_extra(utic, &utic->extras, "use")
cap = _ti_find_extra(rtic, &rtic->extras, "use");