That is to say ? 

```php
$var = array('a' => array('b' => 'c'));
$vaa = array('a' => array('b' => 'd'));
	
var_dump(array_merge($var, $vaa));
```
It outputs array(1) {
  'a' =>
  array(1) {
    'b' =>
    string(1) "d"
  }
}

which is what I expect from it. I don't see why we would need ArrayUtils::merge here.