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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_repos(self, type='', number=-1, etag=None):
 """Iterate over repos for this organization. :param str type: (optional), accepted values: ('all', 'public', 'member', 'private', 'forks', 'sources'), API default: 'all' :param int number: (optional), number of members to return. Default: -1 will return all available. :param str etag: (optional), ETag from a previous request to the same endpoint :returns: generator of :class:`Repository <github3.repos.Repository>` """

        url = self._build_url('repos', base_url=self._api)
        params = {}
        if type in ('all', 'public', 'member', 'private', 'forks', 'sources'):
            params['type'] = type
        return self._iter(int(number), url, Repository, params, etag)