private void send100Continue(ChannelHandlerContext ctx) {
        HttpResponse response = new DefaultHttpResponse(HTTP_1_1, CONTINUE);
        ctx.writeAndFlush(response);
    }
issue: https://github.com/sofastack/sofa-rpc/issues/592
remoting/remoting-resteasy/src/main/java/com/alipay/sofa/rpc/server/rest/SofaRestRequestHandler.java