code: function () {
                  var path, features, index = i;
                  
                  save();
                  
                  var dir = $(/^@import(?:-(once))?\s+/);
  
                  if (dir && (path = $(this.entities.quoted) || $(this.entities.url))) {
                      features = $(this.mediaFeatures);
                      if ($(';')) {
                          return new(tree.Import)(path, imports, features, (dir[1] === 'once'), index);
                      }
                  }
                  
                  restore();
              }
docs: An @import directive  @import "lib";  Depending on our environemnt, importing is done differently: In the browser, it's an XHR request, in Node, it would be a file-system operation. The function used for importing is stored in `import`, which we pass to the Import constructor.