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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 txn_useNonce(self, server_url, timestamp, salt):
 """Return whether this nonce is present, and if it is, then remove it from the set. str -> bool"""

        if abs(timestamp - time.time()) > nonce.SKEW:
            return False

        try:
            self.db_add_nonce(server_url, timestamp, salt)
        except self.exceptions.IntegrityError:
            # The key uniqueness check failed
            return False
        else:
            # The nonce was successfully added
            return True