src/vs/editor/browser/editorDom.ts/DynamicCssRules/createClassNameRef
class DynamicCssRules:	public createClassNameRef(options: CssProperties): ClassNameReference {
		const rule = this.getOrCreateRule(options);
		rule.increaseRefCount();

		return {
			className: rule.className,
			dispose: () => {
				rule.decreaseRefCount();
				this._garbageCollectionScheduler.schedule();
			}
		};
	}