Converts a stored database value to Python.

        :param py_value: <variant>
        :param context: <orb.Context>

        :return: <variant>

def dbRestore(self, db_value, context=None):
        """
        Converts a stored database value to Python.

        :param py_value: <variant>
        :param context: <orb.Context>

        :return: <variant>
        """
        if db_value is None:
            return None
        elif isinstance(db_value, (str, unicode)):
            return self.valueFromString(db_value, context=context)
        else:
            return super(AbstractDatetimeColumn, self).dbRestore(db_value, context=context)