Upsert Sku Deliveries of a Collection. This endpoint is combination of bulk update, bulk create and bulk delete. Colection identifier is "Collection Name". SKU identifier is "sku_external_id" (with addion of "sku_identifier" which can be empty string). If a SKU Delievery record already exist, it will be updated to new value. If a SKU Delivery record does not exists, it will be added. If delivery or both start and complete dates are null, it will be deleted. This endpoint is async, so you will receive a job_id which you can use to check a status. Default limit of objects which can be sent within single request is 20.