code: function ( key ) {
              // `staticAssets`: default namespace of the grunt-static-versioning plugin
              var obj = data.staticAssets[ key ];
              if ( obj && obj.css ) {
                  return obj.css.map( function ( src ) {
                      return '<link rel="stylesheet" href="' + src + '">';
                  } ).join( '\n ' );
              } else {
                  return '';
              }
          }
docs: render all <link> tags based on key