Check if an Object has a Property - hint answer wrong?

Is the answer given in the hint section (see below) correct? I read that hasOwnProperty takes only one argument, if so its just checking the first name and not the rest. If I include another name in the arguments it still returns true and passes which should not be the case?

Your code so far

let users = {
  Alan: {
    age: 27,
    online: true
  Jeff: {
    age: 32,
    online: true
  Sarah: {
    age: 48,
    online: true
  Ryan: {
    age: 19,
    online: true

function isEveryoneHere(obj) {
  // change code below this line
  return obj.hasOwnProperty('Alan', 'Jeff', 'Sarah', 'Ryan', 'Todd') ? true : false
  // change code above this line


Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36.

Link to the challenge:

It’s a known bug