OptionaldereferenceOptionalidentityThe caller's principal id in the guarded resource's own namespace,
resolved as identity() in predicates.
The concrete Lake mutation the action will perform.
The datasource the document lives in. A guard applies solely within the datasource it is registered in, so a same-id match from a foreign datasource can never gate this action and must not flip verdicts.
Resource-local stored-document lookup for predicates using
->.