docs: def get_branch(self, branch):
          """
          :calls: `GET /repos/:owner/:repo/branches/:branch <http://developer.github.com/v3/repos>`_
          :param branch: string
          :rtype: :class:`github.Branch.Branch`
          """
          assert isinstance(branch, (str, unicode)), branch
          headers, data = self._requester.requestJsonAndCheck(
              "GET",
              self.url + "/branches/" + branch
          )
          return github.Branch.Branch(self._requester, headers, data, completed=True)