Function validate_marker_source 

pub async fn validate_marker_source(
    store: Arc<dyn DurableStore>,
    retained: RetainedFencedMarkerSource,
    marker_source_sequence: u64,
) -> Result<ValidatedFencedMarkerInputs, Box<MarkerSourceRefused>>

Point-reads and validates one durable marker source before the retained owner may proceed to its private one-use authority mint.

Errors

Returns a typed refusal containing the unchanged retained inputs when the row is absent, unreadable, has the wrong kind, or disagrees with frontier truth.