var recv: Instance = new MutableInstance(mtype)
v.init_instance(recv)
var args = v.varargize(callsite.mpropdef, recv, self.n_args.n_exprs)
var recv: Instance = new MutableInstance(mtype)
v.init_instance(recv)
var args = v.varargize(callsite.mpropdef, recv, self.n_args.n_exprs)