public static function getDescriptions($function_name)
    {
        if (is_string($function_name))
            $reflection = new ReflectionFunction($function_name);
        elseif (is_array($function_name))
            $reflection = new ReflectionMethod($function_name[0], $function_name[1]);
        else
            throw new LogicException();

        $comment = $reflection->getDocComment();

        $lines = explode("\n", $comment);
        $obj = new self($lines);

        return array(trim($obj->short_desc), trim($obj->long_desc));
    }