message: fix default root class
diff: @@ -37,7 +37,9 @@ export class Stylesheet {
  _kind = "Stylesheet";
  constructor(cssDefinition: CSSObject, namespace: string = "") {
  this.cssDefinition = cssDefinition;
  - this.classes = {};
  + this.classes = {
  + root: 'root'
  + };
  this.vars = {};
  this.typedClasses = {
  root: { "-sb-root": true }
  