class ApplicationStartError(Exception):
    pass


class DateValidatorError(Exception):
    pass


class StackError(Exception):
    pass


class PersonValidatorError(Exception):
    pass


class PersonRepositoryError(Exception):
    pass


class PersonServiceError(Exception):
    pass


class ActivityValidatorError(Exception):
    pass


class ActivityRepositoryError(Exception):
    pass


class ActivityServiceError(Exception):
    pass
