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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 leave_group(self, group_id, timeout=None):
 """Call leave group API. https://devdocs.line.me/en/#leave Leave a group. :param str group_id: Group ID :param timeout: (optional) How long to wait for the server to send data before giving up, as a float, or a (connect timeout, read timeout) float tuple. Default is self.http_client.timeout :type timeout: float | tuple(float, float) """

        self._post(
            '/v2/bot/group/{group_id}/leave'.format(group_id=group_id),
            timeout=timeout
        )