src/vs/workbench/contrib/extensions/browser/extensionsViewer.ts/ExtensionData/getChildren
class ExtensionData:	async getChildren(): Promise<IExtensionData[] | null> {
		if (this.hasChildren) {
			const result: IExtension[] = await getExtensions(this.childrenExtensionIds, this.extensionsWorkbenchService);
			return result.map(extension => new ExtensionData(extension, this, this.getChildrenExtensionIds, this.extensionsWorkbenchService));
		}
		return null;
	}