I have multiple divs like this:

```
<div class="small"></div>
<div class="small"></div>
<div class="small"></div>
<div class="small"></div>

<div class="large"></div>
<div class="large"></div>

<div class="small"></div>
<div class="small"></div>
<div class="small"></div>
<div class="small"></div>
<div class="small"></div>
<div class="small"></div>
<div class="small"></div>
<div class="small"></div>

```

I want to select every 4 .small divs to wrap in another div so it's like this:

```
<div class="box">
    <div class="small"></div>
    <div class="small"></div>
    <div class="small"></div>
    <div class="small"></div>
</div>

```

As you can see from the first example, there can be more than 4 adjacent ones, but I still want to group every 4 .small divs. 

Any idea would be much appreciated. Thanks!