def run_callbacks_for(name, args, reverse)
      callbacks_for(name, reverse).map do |block|
        run_callback(block, args)
      end
    end
def run_callbacks_for(name, args, reverse)
      callbacks_for(name, reverse).map do |block|
        run_callback(block, args)
      end
    end
Run specific callbacks.

   run_callbacks_for(:before_fetch)
   run_callbacks_for(:progress, 12) # 12 percent done