code: def ips(self) -> Optional[List[str]]:
          
          if self.proxy and "X-Forwarded-For" in self._headers:
              val = cast(str, self.get('X-Forwarded-For'))
              ips = [i.strip() for i in val.split(",")]
              return ips if len(ips) > 0 else None
          return None
docs: 获取远端代理ip