问Node.js HTTPS POST请求头

EN

var https = require('https');

var options = {
    host: 'graph.facebook.com',
    port: 443,
    path: '/'+group_id+'/feed?access_token='+access_token,
    method: 'POST',
    headers: { 'message': text }
};

var req = https.request(options, function(res) {
    console.log("statusCode: ", res.statusCode);
    console.log("headers: ", res.headers);

    res.on('data', function(d) {
        process.stdout.write(d);
    });
});

req.end();

statusCode:  400
headers:  { 'cache-control': 'no-store',
  'content-type': 'text/javascript; charset=UTF-8',
  expires: 'Sat, 01 Jan 2000 00:00:00 GMT',
  p3p: 'CP="Facebook does not have a P3P policy. Learn why here: http://fb.me/p3p"',
  pragma: 'no-cache',
  'www-authenticate': 'OAuth "Facebook Platform" "invalid_request" "(#100) A post to a group must have at least a message or attachment"',
  'x-fb-rev': '443252',
  'set-cookie': [ 'datr=removed; expires=Tue, 17-Sep-2013 12:18:08 GMT; path=/; domain=.facebook.com; httponly' ],
  'x-fb-server': '10.62.5.40',
  connection: 'close',
  date: 'Sun, 18 Sep 2011 12:18:08 GMT',
  'content-length': '115' }
{"error":{"message":"(#100) A post to a group must have at least a message or attachment","type":"OAuthException"}}