# File lib/merb-assets/assets.rb, line 181
      def bundle!
        # TODO: push it out to the helper level so we don't have to create the helper object.
        unless self.class.cached_bundle?(@bundle_name)
          # skip regeneration of new bundled files - preventing multiple merb apps stepping on eachother
          # file needs to be older than 60 seconds to be regenerated
          if File.exist?(@bundle_filename) && File.mtime(@bundle_filename) >= Time.now - 60
            return @bundle_name # serve the old file for now - to be regenerated later
          end
          bundle_files(@bundle_filename, *@files)
          if File.exist?(@bundle_filename)
            self.class.callbacks.each { |c| c.call(@bundle_filename) }
            Merb.logger.info("Assets: bundled :#{@bundle_name} into #{File.basename(@bundle_filename)}")
            self.class.cache_bundle(@bundle_name)
          end
        end
        return @bundle_name
      end