Flow\Helper::range PHP Méthode

    public static function range($lower = null, $upper = null, $step = 1)
    {
        return new Helper\RangeIterator(intval($lower), intval($upper), intval($step));
    }

 public function test_range()
 {
     $this->assertTrue(Helper::range(1, 10) instanceof Helper\RangeIterator);
 }