src/vs/workbench/contrib/comments/browser/commentThreadZoneWidget.ts/ReviewZoneWidget/collapse
class ReviewZoneWidget:	public collapse(): Promise<void> {
		this._commentThread.collapsibleState = languages.CommentThreadCollapsibleState.Collapsed;
		if (this._commentThread.comments && this._commentThread.comments.length === 0) {
			this.deleteCommentThread();
			return Promise.resolve();
		}

		this.hide();
		return Promise.resolve();
	}