@SuppressWarnings("unchecked") protected boolean addTelegramListener(TelegramListener newListener){
  return (TelegramListeners.add(newListener));
}

@ SuppressWarnings ( "unchecked" ) protected boolean addTelegramListener ( TelegramListener newListener ) { return ( TelegramListeners . add ( newListener ) ) ; }
add a new listener to be notified about new telegrams
