/**
 * Callback function for the 'webmention_links' filter.
 *
 * @param mixed $urls 
 * @param mixed $post_id 
 * @return mixed The filtered value.
 */
function my_webmention_links_callback( $urls, $post_id ) {
    // Your code here.
    return $urls;
}
add_filter( 'webmention_links', 'my_webmention_links_callback', 10, 2 );

apply_filters( 'webmention_links', $urls, $post_id )