public function header($name, $default = null, $sanitize = true)
    {
        $headers = $this->headers();

        $name = ucfirst(strtolower($name));

        if (array_key_exists($name, $headers)) {
            return $sanitize ? filter_var($headers[$name], FILTER_SANITIZE_STRING) : $headers[$name];
        }

        return $default;
    }