code: private void insert(ArrayList<String> list, String input) {
  		if (!list.contains(input)) {
  			if (input.equals("a") || input.equals("rdf:type")) {
  				list.add(0, input);
  			} else {
  				list.add(input);
  			}
  		}
  	}
docs: Utility method to insert the predicate