How can I add a dynamic property with multiple attributes?
I tried with backticks, but it did not work. 

```
function User(userID){
   this.userID = userID;
   this.printUserDetails = function(){
       console.log(userID);
   }
}

const user=new User('A1234');

user.tokenID='jsessionID=12345678';

user.tokenValidity={
    startDate:07042020
    //What is the syntax to add end date here for e.g. endDate:08042020?
}

```