def page_expired?(page)
      return false if @options[:ttl_page].nil?
      stored_page = @storage.get(page)
      r = stored_page && stored_page.expired?(@options[:ttl_page])
      @logger.debug { "Page #{page.url} marked as expired" } if r
      r
    end
def page_expired?(page)
      return false if @options[:ttl_page].nil?
      stored_page = @storage.get(page)
      r = stored_page && stored_page.expired?(@options[:ttl_page])
      @logger.debug { "Page #{page.url} marked as expired" } if r
      r
    end
whether a page is expired or not