/**
* Generates semantic classes for each comment element.
*
* @since 2.7.0
*
* @param string|array $class Optional. One or more classes to add to the class list.
* Default empty.
* @param int $comment_id Comment ID. Default current comment.
* @param int|WP_Post $post_id Post ID or WP_Post object. Default current post.
* @param bool $echo Optional. Whether to cho or return the output.
* Default true.
* @return string|void
*/
function comment_class( $class = '', $comment_id = null, $post_id = null, $echo = true ) {
// Separates classes with a single space, collates classes for comment DIV
$class = 'class="' . join( ' ', get_comment_class( $class, $comment_id, $post_id ) ) . '"';
if ( $echo)
echo $class;
else
return $class;
}