def find_video_by_url(self, video_url):
        """doc: http://open.youku.com/docs/doc?id=44
        """
        url = 'https://openapi.youku.com/v2/videos/show_basic.json'
        params = {
            'client_id': self.client_id,
            'video_url': video_url
        }
        r = requests.get(url, params=params)
        check_error(r)
        return r.json()
doc: http://open.youku.com/docs/doc?id=44