"set origin igp" on FRRouting, possible ?

Hi, I've had a quick grep through The Fabulous Manual (http://docs.frrouting.org/en/latest/bgp.html), and whilst other old friends such as always-compare-med seem to be implemented, there appears to be no mention of "set origin". Is it possible to do this ? If so, could someone update the docs? If not, could someone implement this rather useful feature ! Thanks ! Bob