- }
- }
-
- private void outputResult(final OutputWriter outputWriter, final long timestamp) {
- if (outputWriter instanceof PlainTextWriter) {
- final var writer = (PlainTextWriter) outputWriter;
- writer.println("{}", timestamp);
- } else {
- final var writer = (JsonWriter) outputWriter;
- writer.write(Map.of("timestamp", timestamp));
+ } catch (UnregisteredRecipientException e) {
+ throw new UserErrorException("The user " + e.getSender().getIdentifier() + " is not registered.");