bouncer from child department

gistfile1.txt

        $user = Auth::user();

        if ($user->can($ability, $modelOrItem)) {
            return true;
        }

        $descendants = $user->departments()->with('descendants')->get();

        foreach ($descendants as $descendant) {
            if ($descendant->can($ability, $modelOrItem)) {
                return true;
            }
        }

        $unionAllChildsDepartments = self::unionOfDescendants($descendants);

        foreach ($unionAllChildsDepartments as $childsDepartments) {
            if ($childsDepartments->can($ability, $modelOrItem)) {
                return true;
            }
        }

        return false;
    }

    private static function unionOfDescendants($descendants)
    {
        $union = collect();
        foreach ($descendants as $descendant) {
            $union = $union->union($descendant->descendants);
        }
        return $union;
    }