    # File lib/action_view/helpers/asset_tag_helper.rb, line 273
          def javascript_include_tag(*sources)
            options = sources.extract_options!.stringify_keys
            concat  = options.delete("concat")
            cache   = concat || options.delete("cache")
            recursive = options.delete("recursive")

            if concat || (ActionController::Base.perform_caching && cache)
              joined_javascript_name = (cache == true ? "all" : cache) + ".js"
              joined_javascript_path = File.join(joined_javascript_name[/^#{File::SEPARATOR}/] ? ASSETS_DIR : JAVASCRIPTS_DIR, joined_javascript_name)

              unless ActionController::Base.perform_caching && File.exists?(joined_javascript_path)
                write_asset_file_contents(joined_javascript_path, compute_javascript_paths(sources, recursive))
              end
              javascript_src_tag(joined_javascript_name, options)
            else
              expand_javascript_sources(sources, recursive).collect { |source| javascript_src_tag(source, options) }.join("\n")
            end
          end