code: public final Set<WriteFuture> broadcast(Object message) {
          // Convert to Set.  We do not return a List here because only the
          // direct caller of MessageBroadcaster knows the order of write
          // operations.
          final List<WriteFuture> futures = IoUtil.broadcast(message,
                  getManagedSessions().values());
          return new AbstractSet<WriteFuture>() {
              @Override
              public Iterator<WriteFuture> iterator() {
                  return futures.iterator();
              }
  
              @Override
              public int size() {
                  return futures.size();
              }
          };
      }
docs: {@inheritDoc}