def get_free_shipping_promotion_by_id(cls, free_shipping_promotion_id, **kwargs):
        """Find FreeShippingPromotion

        Return single instance of FreeShippingPromotion by its ID.
        This method makes a synchronous HTTP request by default. To make an
        asynchronous HTTP request, please pass async=True
        >>> thread = api.get_free_shipping_promotion_by_id(free_shipping_promotion_id, async=True)
        >>> result = thread.get()

        :param async bool
        :param str free_shipping_promotion_id: ID of freeShippingPromotion to return (required)
        :return: FreeShippingPromotion
                 If the method is called asynchronously,
                 returns the request thread.
        """
        kwargs['_return_http_data_only'] = True
        if kwargs.get('async'):
            return cls._get_free_shipping_promotion_by_id_with_http_info(free_shipping_promotion_id, **kwargs)
        else:
            (data) = cls._get_free_shipping_promotion_by_id_with_http_info(free_shipping_promotion_id, **kwargs)
            return data