'Iterate over comments on this gist.
:param int number: (optional), number of comments to iterate over.
Default: -1 will iterate over all comments on the gist
:param str etag: (optional), ETag from a previous request to the same
endpoint
:returns: generator of
:class:`GistComment <github3.gists.comment.GistComment>`'

def comments(self, number=(-1), etag=None):

    url = self._build_url(u'comments', base_url=self._api)
    return self._iter(int(number), url, GistComment, etag=etag)
