The budget splitter api requires a line_item_id but unlike the usual behaviour, it is not passed as a query parameter: https://wiki.xandr.com/display/api/Splits+Service It's `https://api.appnexus.com/budget-splitter/LINE-ITEM-ID/splits` instead of `https://api.appnexus.com/budget-splitter?line_item_id=LINE-ITEM-ID`