BetterResultUseCaseExample.kt

class GetMagicCardUseCase(
    private val magicCardsRepository: MagicTheGatheringCardsRepository
) {

    suspend operator fun invoke(cardName: String) : Result<MagicCard, GetMagicCardUseCaseError> {
        if (!isCardNameValid(cardName)) {
            return Error(InvalidCardNameFormat)
        }
        //...
        return magicCardsRepository.getCard(cardName)
    }

}