https通信をHTTP Proxy経由でおこない、SJISなページを文字化けさせずにSJISエンコードでファイルに保存する

httpsWithProxy.js

var fs = require('fs');
var tunnel = require('tunnel');
var tunnelAg = tunnel.httpsOverHttp({
    proxy: {
        host: '192.168.0.1',
        port: 8080
    }
});
 
var https = require('https');
options = {
    host: 'www.google.co.jp',
    port: 443,
    path: '/',
    agent: tunnelAg
};
https.get(options, function (res) {
var hdr = res.headers;
//hdr[];
console.log('HEADERS: ' + JSON.stringify(res.headers));
//res.setEncoding('utf8');
var length = 0;
var content=new Buffer([]);
    res.on('data', function (chunk) {
        //console.log(chunk.toString());
        content = Buffer.concat([content,chunk]);
    });
    res.on('end', function() {
        console.log(content.toString("binary"));
        fs.writeFileSync("dump00.txt",content,{encoding:null});
    })
});