@typecheck_method(cond=IR, agg_ir=IR)
def copy(self, cond, agg_ir):
    new_instance = self.__class__
    return new_instance(cond, agg_ir)
@typecheck_method(cond=IR, agg_ir=IR)
def copy(self, cond, agg_ir):
    new_instance = self.__class__
    return new_instance(cond, agg_ir)