) throws UnregisteredUserException {
final Optional<Recipient> byNumber;
synchronized (recipients) {
byNumber = findByNumberLocked(number);
}
if (byNumber.isEmpty() || byNumber.get().getAddress().getUuid().isEmpty()) {
) throws UnregisteredUserException {
final Optional<Recipient> byNumber;
synchronized (recipients) {
byNumber = findByNumberLocked(number);
}
if (byNumber.isEmpty() || byNumber.get().getAddress().getUuid().isEmpty()) {