code: def issue(self, number):
          
          json = None
          if int(number) > 0:
              url = self._build_url('issues', str(number), base_url=self._api)
              json = self._json(self._get(url), 200)
          return Issue(json, self) if json else None
docs: Get the issue specified by ``number``.
  
          :param int number: (required), number of the issue on this repository
          :returns: :class:`Issue <github3.issues.issue.Issue>` if successful,
              otherwise None