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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 stock_status(self, stock_status):
 """Sets the stock_status of this Product. :param stock_status: The stock_status of this Product. :type: str """

        allowed_values = ["available", "alert", "unavailable"]
        if stock_status is not None and stock_status not in allowed_values:
            raise ValueError(
                "Invalid value for `stock_status` ({0}), must be one of {1}"
                .format(stock_status, allowed_values)
            )

        self._stock_status = stock_status