code: public void removeGroup(String groupId) {
  		for (Iterator<QueryControllerEntity> iterator = entities.iterator(); iterator.hasNext();) {
  			Object temporal = iterator.next();
  			if (!(temporal instanceof QueryControllerGroup)) {
  				continue;
  			}
  			QueryControllerGroup element = (QueryControllerGroup) temporal;
  			if (element instanceof QueryControllerGroup) {
  				QueryControllerGroup group = element;
  				if (group.getID().equals(groupId)) {
  					entities.remove(group);
  					fireElementRemoved(group);
  					return;
  				}
  			}
  		}
  	}
docs: Removes a group from the vector QueryControllerEntity