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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 _setdefault(self, key, default=None):
 """ If ``key`` is not present, set it as ``default`` and return it. If ``key`` is present, return its value. :param key: Key to add to Zookeeper :type key: string :param default: Default object to return if ``key`` is present. :type default: object Will retry trying to get or create a node based on the "retry" config from the Kazoo client. """

        return self.connection.retry(self.__inner_set_default, key, default)