Given the following code:

```
function Person(firstName, lastName) {
    this.FirstName = firstName;
    this.LastName = lastName;
}

Person.prototype.showFullName = function() {
    return this.FirstName + " " + this.LastName;
};

var person = new Person("xx", "xxxx");
var jsonString = JSON.stringify(person);

var thePerson = JSON.parse(jsonString);

```

My goal here would be to be able to call "showFullName" on thePerson. While I understand that JS does not really have objects, it must have some way of being able to say something should be treated a certain way, like casting `thePerson` to a `Person`.