/** * Comparison function for sorting literals by their id * * @param Literal $a * @param Literal $b * @return int 0 if the literals are equal, 1 if b is larger than a, -1 else */ private function compareLiteralsById(Literal $a, Literal $b) { if ($a->getId() === $b->getId()) { return 0; } return $a->getId() < $b->getId() ? -1 : 1; }