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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 _manage_used_ips(self, current_ip):
 """ Handle registering and releasing used Tor IPs. :argument current_ip: current Tor IP :type current_ip: str """

        # Register current IP.
        self.used_ips.append(current_ip)

        # Release the oldest registred IP.
        if self.reuse_threshold:
            if len(self.used_ips) > self.reuse_threshold:
                del self.used_ips[0]