class ServiceError(Exception):
    pass


class UserAlreadyExistsError(ServiceError):
    pass


class ExchangeAlreadyExistsError(ServiceError):
    pass


class ExchangeNotFoundError(ServiceError):
    pass


class CycleNotFoundError(ServiceError):
    pass


class TradeNotFoundError(ServiceError):
    pass


class InvalidTradeDataError(ServiceError):
    pass


class InvalidCycleDataError(ServiceError):
    pass


class CycleLoanEventExistsError(ServiceError):
    pass