make 2 seperate functions: one for themed items, and one for items array for more flexibility

function theme_similar_content($node) returns theme('item_list', $items). but as a developer i want to use those $items before they are themed. So it should be separated into 2 functions. The first receives the $node object (maybe more than 1 node, but that's for another task) and returns $items array. And the second function receives $items array and returns the themed list from the items.
It's a pretty easy task, yet crucial.