How to mock canister with existing method?

[Maximkaaa]

Hi. Amazing library! Can you please provide some insight on how to mock a canister with existing methods.

Say, I have a method

#[update]
async fn do_nothing(my_arg: u64) -> Result<(), String> {
    Ok(())
}

How would I create a Canister mock with the method above? I've tried to use RawHandler, but cannot figure out how to transfer arguments correctly.

The way I want to use it later is like so:

let canister = Canister::new(mock_principals::alice())
    .method("do_nothing", ...);

let ctx = canister.context().inject();
ic::call_with_payment(mock_principals::alice(), "do_nothing", (1000), 100);

Is it even possible with the current implementation?