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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def iter_forks(self, number=-1, etag=None):
 """Iterator of forks of this gist. .. versionchanged:: 0.9 Added params ``number`` and ``etag``. :param int number: (optional), number of forks to iterate over. Default: -1 will iterate over all forks of this gist. :param str etag: (optional), ETag from a previous request to this endpoint. :returns: generator of :class:`Gist <Gist>` """

        url = self._build_url('forks', base_url=self._api)
        return self._iter(int(number), url, Gist, etag=etag)