i saw this PR: https://github.com/authzed/spicedb/pull/858/files# is there documentation and/or a parser for that format somewhere, or is it on the consumer to write their own parser? this is an example of what I get for a precondition error:

FAILED_PRECONDITION: unable to satisfy write precondition
   `operation:OPERATION_MUST_MATCH filter:{resource_type:"persona"
   optional_resource_id:"p4" optional_relation:"user"
   optional_subject_filter:{subject_type:"user" optional_subject_id:"aamFuZQ"}}`

which is almost json, but not quite, and I think I'd have to write a custom parser in our language for it.