code: def _manage_used_ips(self, current_ip):
          
          # 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]
docs: Handle registering and releasing used Tor IPs.
  
          :argument current_ip: current Tor IP
          :type current_ip: str