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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def release(cls, entity, unit_of_work):
 """ Releases the given entity from management under the given Unit Of Work. :raises ValueError: If `entity` is not managed at all or is not managed by the given Unit Of Work. """

        if not hasattr(entity, '__everest__'):
            raise ValueError('Trying to unregister an entity that has not '
                             'been registered yet!')
        elif not unit_of_work is entity.__everest__.unit_of_work:
            raise ValueError('Trying to unregister an entity that has been '
                             'registered with another session!')
        delattr(entity, '__everest__')