@Override
  public Set<IConnection> getAllConnection() {

    Set<IConnection> conns = new HashSet<IConnection>();
    conns.addAll(ch1.getAllConnection());
    conns.addAll(ch2.getAllConnection());

    return conns;
  }
 @Override
 public void cancel() {
   ch1.cancel();
   ch2.cancel();
 }
 @Override
 public void kill() {
   ch1.kill();
   ch2.kill();
 }