public function whereBetween($name, $first_value, $last_value = null)
    {

        if (is_array($first_value) && count($first_value) == 2) {
            $last_value = $first_value[1];
            $first_value = $first_value[0];
        }

        $this->filter[] = ["range" => [$name => ["gte" => $first_value, "lte" => $last_value]]];

        return $this;
    }