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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 return_action(self, return_action):
 """Sets the return_action of this ReturnSettings. :param return_action: The return_action of this ReturnSettings. :type: str """

        allowed_values = ["refund", "storeCredit"]  # noqa: E501
        if return_action is not None and return_action not in allowed_values:
            raise ValueError(
                "Invalid value for `return_action` ({0}), must be one of {1}"  # noqa: E501
                .format(return_action, allowed_values)
            )

        self._return_action = return_action