Is this necessary to add class through hreview_echo

Hi Yoast,

Thank for the article to implement hreview https://yoast.com/implement-hreview-wordpress-theme/

I am currently implementing it in Woothemes Canvas theme. But facing some issues. Is this necessary to add required classes through hreview_echo function. I can add classes e.g hard coding.

Issue is in adding class “item fn” to title. I have done it like this but its not working

$title_before = '<h1 class="title';
 $title_after = '</h1>';

 $title_before = $title_before .  hreview_echo(' item fn') . '"><a href="' . get_permalink( get_the_ID() ) . '" rel="bookmark" title="' . the_title_attribute( array( 'echo' => 0 ) ) . '">';
$title_after = '</a>' . $title_after;

Thank You
https://www.ads-software.com/plugins/wordpress-seo/