code: def mark_good(self, proxy):
          
          if proxy not in self.proxies:
              logger.warn("Proxy <%s> was not found in proxies list" % proxy)
              return
  
          if proxy not in self.good:
              logger.debug("Proxy <%s> is GOOD" % proxy)
  
          self.unchecked.discard(proxy)
          self.dead.discard(proxy)
          self.good.add(proxy)
          self.proxies[proxy].failed_attempts = 0
docs: Mark a proxy as good