markDead
Mark a request as permanently failed (dead) with an optional response.
Return
If the request was successfully marked as dead, returns a success with Unit
If the request is not found, the result will be a failure with PostboxError.RequestNotFound
If the request has been already processed, the result will be a failure with PostboxError.StorageFailure
Parameters
requestId
the id of the request to mark as dead
response
the response to store with the dead request (optional)
If a response was not previously stored, the new response will be stored. Subsequent responses will be ignored.