code: def iter_commits(self, number=-1, etag=None):
          
          url = self._build_url('commits', base_url=self._api)
          return self._iter(int(number), url, GistHistory)
docs: Iter over the commits on this gist.
  
          These commits will be requested from the API and should be the same as
          what is in ``Gist.history``.
  
          .. versionadded:: 0.6
  
          .. versionchanged:: 0.9
  
              Added param ``etag``.
  
          :param int number: (optional), number of commits to iterate over.
              Default: -1 will iterate over all commits associated with this
              gist.
          :param str etag: (optional), ETag from a previous request to this
              endpoint.
          :returns: generator of
              :class:`GistHistory <github3.gists.history.GistHistory>`