Add an extra value to generic-helper.class.php

Hi there,

I would like to add an extra value to the function av_mobile_sizes. As far I can see, there $columns has these values:

$columns = array('av-medium-columns', 'av-small-columns', 'av-mini-columns');

I would like to add to that array an extra value called: av-high-columns. There is any way to do it with a child theme?

Thanks