Limit Previous & Next Post Links to Articles in Same Category

Hello, I am trying to limit the "previous" and "next post" links after the content on my single posts pages to the same taxonomy as the post itself, i.e., preferably by category. I have found some helpful WP articles: http://codex.wordpress.org/Function_Reference/next_post_link http://codex.wordpress.org/Function_Reference/previous_post_link but I can't find the "in_same_term" parameter mentioned in those articles in Catch Everest Pro's single.php file or any where else. Thanks for a great theme. I am very close to going live. Any help would be greatly appreciated!