def unwrap(self, value, session=None):
        ''' Validate and then unwrap ``value`` for object creation.

            :param value: list returned from the database.
        '''
        self.validate_unwrap(value)
        ret = []
        for field, value in izip(self.types, value):
            ret.append(field.unwrap(value, session=session))
        return tuple(ret)
Validate and then unwrap ``value`` for object creation.

            :param value: list returned from the database.