BYOC CodeGen for customized Call Node/Operator

Hi, how should I set the add_implementation function at the Relay frontend when I decide to use BYOC? Since I will not use the operator from topi

@override_native_generic_func("cumprod_strategy")
def cumprod_strategy(attrs, inputs, out_type, target):
    """cumprod generic strategy"""
    strategy = _op.OpStrategy()
    strategy.add_implementation(
        wrap_compute_scanop(topi.cumprod),
        wrap_topi_schedule(topi.generic.schedule_extern),
        name="cumprod.generic",
    )
    return strategy

@cumsum_strategy.register(["cuda", "gpu"])
def cumsum_strategy_cuda(attrs, inputs, out_type, target):
    """cumsum cuda strategy"""
    strategy = _op.OpStrategy()
    strategy.add_implementation(
        wrap_compute_scanop(topi.cuda.cumsum),
        wrap_topi_schedule(topi.cuda.schedule_scan),
        name="cumsum.cuda",
    )
    return strategy