class ComputationException(Exception):
    pass


class MapException(ComputationException):
    def __init__(self, message, results):
        super(MapException, self).__init__(message)
        self.results = results


class LoopDetectedException(ComputationException):
    pass


class NonExistentNodeException(ComputationException):
    pass


class NodeAlreadyExistsException(ComputationException):
    pass
