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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 get_nested_group_users(self, groupname):
 """Retrieves a list of all users that directly or indirectly belong to the given groupname. Args: groupname: The group name. Returns: list: A list of strings of user names. """


        response = self._get(self.rest_url + "/group/user/nested",
                             params={"groupname": groupname,
                                     "start-index": 0,
                                     "max-results": 99999})

        if not response.ok:
            return None

        return [u['name'] for u in response.json()['users']]