src/vs/workbench/contrib/extensions/browser/extensionsViewer.ts/UnknownExtensionRenderer/renderElement
class UnknownExtensionRenderer:	public renderElement(node: ITreeNode<IExtensionData>, index: number, data: IUnknownExtensionTemplateData): void {
		data.identifier.textContent = node.element.extension.identifier.id;
	}