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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_rollup_ttl(self, use_cached=True):
 """Retrieve the rollupTtl for this stream The rollupTtl is the time to live (TTL) in seconds for the aggregate roll-ups of data points stored in the stream. A roll-up expires after the configured amount of time and is automatically deleted. :param bool use_cached: If False, the function will always request the latest from Device Cloud. If True, the device will not make a request if it already has cached data. :raises devicecloud.DeviceCloudHttpException: in the case of an unexpected http error :raises devicecloud.streams.NoSuchStreamException: if this stream has not yet been created :return: The rollupTtl associated with this stream in seconds :rtype: int or None """

        rollup_ttl_text = self._get_stream_metadata(use_cached).get("rollupTtl")
        return int(rollup_ttl_text)