substituteOnReject property
Asked when POLICY (not transport) rejects a guaranteed frame, at enqueue
size check or at delivery. A non-null result is delivered in its place,
without the policy guard — it must carry no screen content. This is how
a request/response frame the backend is waiting on (info_query_response,
find_candidates_response) becomes an explicit failure instead of a
silent drop that leaves the agent waiting for a timeout.
Implementation
final Uint8List? Function(String type, Uint8List bytes, String reason)?
substituteOnReject;