src/vs/workbench/contrib/comments/browser/commentsTreeViewer.ts/CommentsAsyncDataSource/getChildren
class CommentsAsyncDataSource:	getChildren(element: any): any[] | Promise<any[]> {
		if (element instanceof CommentsModel) {
			return Promise.resolve(element.resourceCommentThreads);
		}
		if (element instanceof ResourceWithCommentThreads) {
			return Promise.resolve(element.commentThreads);
		}
		return Promise.resolve([]);
	}