digest

Returns a compact summary of which spans this producer has already delivered to the edge (producer-local — see SpanDigest).

The bridge subtracts this set from its local CRDT snapshot to compute the delta: only spans absent from the digest are sent over the wire.

Throws on connectivity failure; WarpOtlpBridge wraps the call with runCatchingCancellable and surfaces the error as DrainResult.Failure.