Class example of action function 1

class emailer {
  function send($post_ID)  {
    $users = 'bob@example.org,susie@example.org';
    mail($users,"sally's blog updated",'I just put something on my blog: http://blog.example.com');
    return $post_ID;
  }
}

add_action('publish_post', array('emailer', 'send'));