+ final var writer = new PlainTextWriterImpl(System.out);
+
+ final Pair<Long, List<SendMessageResult>> results;
+
+ GroupId groupId = null;
+ if (groupId != null) {
+ try {
+ groupId = Util.decodeGroupId(groupIdString);
+ } catch (GroupIdFormatException e) {
+ throw new UserErrorException("Invalid group id:" + e.getMessage());
+ }
+ }
+