process_attributes_for (HTML::WhiteListSanitizer)

    # File lib/action_controller/vendor/html-scanner/html/sanitizer.rb, line 155
        def process_attributes_for(node, options)
          return unless node.attributes
          node.attributes.keys.each do |attr_name|
            value = node.attributes[attr_name].to_s

            if !options[:attributes].include?(attr_name) || contains_bad_protocols?(attr_name, value)
              node.attributes.delete(attr_name)
            else
              node.attributes[attr_name] = attr_name == 'style' ? sanitize_css(value) : CGI::escapeHTML(value)
            end
          end
        end