SetupGracefulStop grace stop.

ShutDown http shutdown.

WithDevMode 开启调试模式, 默认情况下会读取DEBUG变量.

WithDumpAll 开启请求/响应的详细日志.

WithoutProxy 禁用代理, 默认情况下会读取HTTP_PROXY/HTTPS_PROXY/http_proxy/https_proxy变量.

WithUserAgent 设置请求的User-Agent.