'Create a comment on this gist.
:param str body: (required), body of the comment
:returns: :class:`GistComment <github3.gists.comment.GistComment>`'

@requires_auth
def create_comment(self, body):

    json = None
    if body:
        url = self._build_url(u'comments', base_url=self._api)
        json = self._json(self._post(url, data={u'body': body}), 201)
    return self._instance_or_null(GistComment, json)
