[Plugin: WP Widget Cache] Cache widgets with different content per page/category

How to do caching of widgets with different content per page:
Open widget-cache.php, then
Find: "currentCategory"=>array(&$this,'get_current_category'),
Add after: "currentPost"=>array(&$this,'get_current_post'),

Find: function get_widget_cache_key($id)
Add before:

function get_current_post(){
  if(is_single()){
    global $post;
    return $post->ID;
  }
  return false;
}