code: function (type, group) {
      var name = path.join(config.packed, group + '.' + type);
      var parsed = filter.get('target', type)(name) || name;
      var html = toHtml(type, path.join(config.root, parsed));
      var target = fss.target(parsed);
      if (fss.exists(target)) return html;
  
      log('packing', fss.baseRelative(target));
      var files = assetFiles(type, group);
      if (_.isArray(files) && files.length > 0) {
          filter.get('pack', type)(files, function(packed) {
              fss.writeFile(target, packed);
          });
      }
  
      return html;
  }
docs: /*
  Serve assets in build mode, by concatenating and miniying resources.