<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def team(self, team_id):
 """Returns Team object with information about team specified by ``team_id``. :param int team_id: (required), unique id for the team :returns: :class:`Team <Team>` """

        json = None
        if int(team_id) > 0:
            url = self._build_url('teams', str(team_id))
            json = self._json(self._get(url), 200)
        return Team(json, self._session) if json else None