检测 HTTP、SOCKS4 和 SOCKS5 代理：是否响应、速度多快、对方看到的是哪个地址。
Accepts host:port, host:port:user:pass, user:pass@host:port and forms that name the protocol such as socks5://. Without a protocol the type is detected.
选对类型比依次尝试三种协议快得多。
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