not sure about the naming here as it only returns the used fee
also it could be convenient to return more data, not only the fee (gas price, gas used, ...) which doesn't have to be extracted separately from tx-result if there is no interest in any other data of tx-result
e.g.
withFee, see https://github.com/aeternity/state-channel-demo/blob/develop/contract/test/game.test.js#L29failsWith, see https://github.com/aeternity/state-channel-demo/blob/develop/contract/test/game.test.js#L59anything else important @bogdan-manole?
what's important and generally usable in https://github.com/aeternity/lqty-contracts/tree/feat/lqty/test/shared/utilities ?