Question: I have developed a website for PC using asp.net MVC5. Now trying to develop a mobile supported anonymous access web page for same website using asp.net MVC5. I created a new project for this and downloaded jQuery.Mobile.MVC from Nuget console. This added mobile layout in the project with the JS code 

```js
$(document).ready(function () {
    $.mobile.ajaxEnabled = false; 
});

```

I just added a new view with this mobile layout and added few label controls to see how it works. It throws below error

JavaScript runtime error: Unable to set property 'ajaxEnabled' of undefined or null reference

Do I have to add any other libraries? This is my first mobile page. It would be great if you are help with some good tutorials

I have included jquery.mobile.js references

Thanks

Answer: 
They need to be immutable. And a key feature of correctly implemented immutability is it can't be extended. If you could extend you could do this:

```
class MyInteger extends Integer
{
    private int myOverrideValue;

    @Override
    public int intValue() {
      return myOverrideValue;
    }

    public void setIntValue(int value) {
      myOverrideValue = value;
    }
}

```

Now I can pass around objects of the mutable type `MyInteger` to classes and code that expects `intValue` to not change.
Sorry for this, activating this thread 5 years after, but i can't see any constructive suggestion for a solution - why don't you simply encapsulate it?

```java
public MyInteger {

  private Integer value;

  public MyInteger(Integer value) {
       this.value = value;
  }

//... Add your custom math methods here

}

```

Leaving this here if someone stumbles on this with similar questions :)