code: def iter_subscriptions(self, login=None, number=-1, etag=None):
          
          if login:
              return self.user(login).iter_subscriptions()
  
          url = self._build_url('user', 'subscriptions')
          return self._iter(int(number), url, Repository, etag=etag)
docs: Iterate over repositories subscribed to by ``login`` or the
          authenticated user.
  
          :param str login: (optional), name of user whose subscriptions you want
              to see
          :param int number: (optional), number of repositories to return.
              Default: -1 returns all repositories
          :param str etag: (optional), ETag from a previous request to the same
              endpoint
          :returns: generator of :class:`Repository <github3.repos.Repository>`