def remote_a
      return unless @page_a_tags
      remote_a = []
      @page_a_tags.uniq.each do |link|
        uri = URI(link[0].to_ascii)
        if uri && @site_domain
          remote_a << link[0] unless uri.host == @site_domain
        end
      end
      remote_a
    end
def remote_a
      return unless @page_a_tags
      remote_a = []
      @page_a_tags.uniq.each do |link|
        uri = URI(link[0].to_ascii)
        if uri && @site_domain
          remote_a << link[0] unless uri.host == @site_domain
        end
      end
      remote_a
    end
get all remote link on page