code: def iter_gists(self, username=None, number=-1, etag=None):
          
          if username:
              url = self._build_url('users', username, 'gists')
          else:
              url = self._build_url('gists')
          return self._iter(int(number), url, Gist, etag=etag)
docs: If no username is specified, GET /gists, otherwise GET
          /users/:username/gists
  
          :param str login: (optional), login of the user to check
          :param int number: (optional), number of gists to return. Default: -1
              returns all available gists
          :param str etag: (optional), ETag from a previous request to the same
              endpoint
          :returns: generator of :class:`Gist <github3.gists.Gist>`\ s