An multi-provider injection token for providing extra GraphQL fragments that will be spread into cart queries. This can be used to retrieve additional data that is not covered by the standard Daffodil interfaces. The data will appear in DaffCart#extra_attributes. Fragment structure is platform-specific and this feature should be used with care. This can increase query complexity above the Magento default of 300. Daffodil only guarantees that stock queries don't exceed the limit of 300. Apps using this token should therefore increase the query complexity limit to accommodate the extra complexity contributed by the provided fragments.