public function sortBy($criteria)
    {
        $criteria = $this->factoryCallableCriteria($criteria);
        $sorted   = $this->create();
        $groups   = $this->groupBy($criteria);

        $criterias = $this->map(function ($element, $key) use ($criteria) {
            return $criteria($element, $key);
        })->toArray();

        sort($criterias);
        $criterias = array_unique($criterias);

        foreach ($criterias as $key) {
            foreach ($groups[$key] as $element) {
                $sorted[] = $element;
            }
        }

        return $sorted;
    }