code: def gist(self, id_num):
          
          url = self._build_url('gists', str(id_num))
          json = self._json(self._get(url), 200)
          return Gist(json, self) if json else None
docs: Gets the gist using the specified id number.
  
          :param int id_num: (required), unique id of the gist
          :returns: :class:`Gist <github3.gists.Gist>`