code: void clearCroutonsForActivity(Activity activity) {
      Iterator<Crouton> croutonIterator = croutonQueue.iterator();
      while (croutonIterator.hasNext()) {
        Crouton crouton = croutonIterator.next();
        if ((null != crouton.getActivity()) && crouton.getActivity().equals(activity)) {
          // remove the crouton from the content view
          removeCroutonFromViewParent(crouton);
  
          removeAllMessagesForCrouton(crouton);
  
          // remove the crouton from the queue
          croutonIterator.remove();
        }
      }
    }
docs: Removes all {@link Crouton}s for the provided activity. This will remove
  crouton from {@link Activity}s content view immediately.