src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts/ReviewZoneWidget/onEditorMouseUp
class ReviewZoneWidget:	private onEditorMouseUp(e: IEditorMouseEvent): void {
		if (!this.mouseDownInfo) {
			return;
		}

		const { lineNumber } = this.mouseDownInfo;
		this.mouseDownInfo = null;

		const range = e.target.range;

		if (!range || range.startLineNumber !== lineNumber) {
			return;
		}

		if (e.target.type !== MouseTargetType.GUTTER_LINE_DECORATIONS) {
			return;
		}

		if (!e.target.element) {
			return;
		}

		if (this._commentGlyph && this._commentGlyph.getPosition().position!.lineNumber !== lineNumber) {
			return;
		}

		if (e.target.element.className.indexOf('comment-thread') >= 0) {
			this.toggleExpand(lineNumber);
		}
	}