def action_call_on_instance(
            self, obj, ar, ba, request_kwargs={}, **status):
        if ar is None:
            sar = ba.request(**request_kwargs)
        else:
            sar = ar.spawn(ba, **request_kwargs)
        return self.ar2js(sar, obj, **status)
Note that `ba.actor` may differ from `ar.actor` when defined on a
dataset/ETHPy150Open lsaffre/lino/lino/modlib/extjs/ext_renderer.py/ExtRenderer.action_call_on_instance