src/vs/workbench/contrib/comments/browser/commentThreadZoneWidget.ts/ReviewZoneWidget/toggleExpand
class ReviewZoneWidget:	toggleExpand(lineNumber: number) {
		if (this._isExpanded) {
			this._commentThread.collapsibleState = languages.CommentThreadCollapsibleState.Collapsed;
			this.hide();
			if (!this._commentThread.comments || !this._commentThread.comments.length) {
				this.deleteCommentThread();
			}
		} else {
			this._commentThread.collapsibleState = languages.CommentThreadCollapsibleState.Expanded;
			this.show({ lineNumber: lineNumber, column: 1 }, 2);
		}
	}