How to use

keys

function

in

ObjectChain

_.chain(this._public())
   .pick(function(value) { return {String: true, Number: true, Date: true}[value && value.constructor.name]; })
   .keys()
   .value()

http.createServer(function(req, res) {
 var cookies = _(parseCookies(req.headers.cookie))
  .keys()
  .map(function(key) {
   return key.toLowerCase();
  })
  .value()
  .sort();

 var headers = _.chain(req.headers)
  .omit('cookie')
  .keys()
  .map(function(key) {
   return key.toLowerCase();
  })
  .value()
  .sort();

 var body = JSON.stringify({
  headers: headers,
  cookies: cookies
 });

 // simulate server latency
 setTimeout(function() {
  res.writeHead(200, { 'Content-Type': 'application/json' });
  res.end(body);
 }, 500);
}).listen(1337, '0.0.0.0')

clients[userId] = client;
const restOfUsers =  _.chain(clients)
  .keys()
  .filter(c => c !== userId)
  .value();