Question: In the Maven Standard Directory Layout where do I put Rules Engine files? Specifically, I'm using JBoss Rules (Drools), if that matters.

Answer: 
**Simply use `classList.contains()`:**

```
if (document.body.classList.contains('thatClass')) {
    // do some stuff
}

```

**Other uses of `classList`:**

```
document.body.classList.add('thisClass');
// $('body').addClass('thisClass');

document.body.classList.remove('thatClass');
// $('body').removeClass('thatClass');

document.body.classList.toggle('anotherClass');
// $('body').toggleClass('anotherClass');

```

**Browser Support:**

* Chrome 8.0
* Firefox 3.6
* IE 10
* Opera 11.50
* Safari 5.1

[`classList` Browser Support](http://caniuse.com/#search=classList)
a good solution for this is to work with classList and contains.

i did it like this:

```
... for ( var i = 0; i < container.length; i++ ) {
        if ( container[i].classList.contains('half_width') ) { ...

```

So you need your element and check the list of the classes. If one of the classes is the same as the one you search for it will return true if not it will return false!