code: def each_mailto
        return enum_for(__method__) unless block_given?
  
        if (html? && doc)
          doc.search('//a[starts-with(@href,"mailto:")]').each do |a|
            yield a.get_attribute('href')[7..-1]
          end
        end
      end
docs: Enumerates over every `mailto:` link in the page.
  
   @yield [link]
     The given block will be passed every `mailto:` link from the page.
  
   @yieldparam [String] link
     A `mailto:` link from the page.
  
   @return [Enumerator]
     If no block is given, an enumerator object will be returned.
  
   @since 0.5.0