rewrite_asset_path

# File actionpack/lib/action_view/helpers/asset_tag_helper.rb, line 810
        def rewrite_asset_path(source, path = nil)
          if path && path.respond_to?(:call)
            return path.call(source)
          elsif path && path.is_a?(String)
            return path % [source]
          end

          asset_id = rails_asset_id(source)
          if asset_id.blank?
            source
          else
            source + "?#{asset_id}"
          end
        end