docs: def destroy_playlist(self, access_token, playlist_id):
          """doc: http://open.youku.com/docs/doc?id=74
          """
          url = 'https://openapi.youku.com/v2/playlists/destroy.json'
          data = {
              'client_id': self.client_id,
              'access_token': access_token,
              'playlist_id': playlist_id
          }
          r = requests.post(url, data=data)
          check_error(r)
          return r.json()['id']