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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 unlock(self, key, cas):
 """Unlock a Locked Key in Couchbase. This unlocks an item previously locked by :meth:`lock` :param key: The key to unlock :param cas: The cas returned from :meth:`lock`'s :class:`.Result` object. See :meth:`lock` for an example. :raise: :exc:`.TemporaryFailError` if the CAS supplied does not match the CAS on the server (possibly because it was unlocked by previous call). .. seealso:: :meth:`lock` :meth:`unlock_multi` """

        return _Base.unlock(self, key, cas=cas)