MP Stacks + DownloadGrid: How to add the Author to the Title for Grid Items

gistfile1.txt

function my_downloadgrid_add_author_to_title( $post_title, $post_id ){
	
	//Get the author of the post in question
	$post_object = get_post( $post_id );
	$author_id = $post_object->post_author;
	$author_nicename = get_the_author_meta( 'user_nicename', $author_id );
	
	return $post_title . ' | ' . $author_nicename;
	
}
add_filter( 'mp_stacks_downloadgrid_item_title', 'my_downloadgrid_add_author_to_title', 10, 2 );