media_resource_ids.each do |mr_id| 
        existing_up_user_ids = Set.new Userpermission.where("media_resource_id= ?",mr_id).pluck(:user_id)
        (existing_up_user_ids - affected_user_ids).each do |uid|
          Userpermission.find_by(media_resource_id: mr_id, user_id: uid).destroy