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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 renamenx(self, key, newkey):
 """Renames key to newkey only if newkey does not exist. :raises ValueError: if key == newkey """

        if key == newkey:
            raise ValueError("key and newkey are the same")
        fut = self.execute(b'RENAMENX', key, newkey)
        return wait_convert(fut, bool)