I read the hint is bind. I was reading about this method and think I understand it. Any option of solution didn't work. I opened the solution. And I see the most understandable option with "}.bind(this)". I've never seen such syntax "}.methodName"!! How could I guess it is possible??? I'm very sad(

JS: Node v14 should be used along with its appropiate assertion tools (Mocha + Chai).
Refer to this and this

var random = Math.random(); // Can not be guessed

Well, about that

How does the anti-cheat work?

I have the same problerm!

You should provide some test cases.

Your tests never check to see if the private variables are actually private.

Additional test cases would be helpful, and maybe a note on the difference between privelged functions and prototypical functions.

I typed that exact code in the solution and it didn't allow me to pass it.

it asks for privite methods however it needs the method to be written with a ' this. ' for it to work.

+1 for visibility

No Example test provided.

Your test case expect "Sam" to be initialized before you call setName.

A solution with a public variable name can pass the tests, which is not what was expected from the kata description.

True, you could also write that without the extra method variable by binding the function to null and then calling it: instance.getName.bind(null)()