src/vs/platform/extensionManagement/node/extensionManagementService.ts/AbstractInstallExtensionTask/isUninstalled
class AbstractInstallExtensionTask:	private async isUninstalled(extensionId: ExtensionKey): Promise<boolean> {
		const uninstalled = await this.extensionsScanner.getUninstalledExtensions();
		return !!uninstalled[extensionId.toString()];
	}