I've just started looking into what SpiceDB has to offer, and am excited by its potential. I think I'm starting to grok how to define schema and relationships for user centric needs. I am curious, are there any examples of using spiceDB for application to application authorization? I ask because we currently model applications as an identity with multiple attributes such as AWS region and test versus production. I'm looking at how we could model that in spiceDB, but I keep getting stuck when trying to solve for how to map our multi-attributes application identifiers into an identifier we can both WriteRelationships to and CheckPermissionRequest for. An example https://play.authzed.com/s/w3tYqjiojKuJ/relationships The best solution I can come up with would be to require a CheckPermission for every possible combination of application & attribute, but then essentially we're building a policy engine on top of SpiceDB.