code: public void createGroup(String groupId) throws Exception {
  		if (getElementPosition(groupId) == -1) {
  			QueryControllerGroup group = new QueryControllerGroup(groupId);
  			entities.add(group);
  			fireElementAdded(group);
  		}
  		else {
  			throw new Exception("The name is already taken, either by a query group or a query item");
  		}
  	}
docs: Creates a new group and adds it to the vector QueryControllerEntity