src/vs/platform/environment/common/environmentService.ts/AbstractNativeEnvironmentService/extensionsDownloadPath
class AbstractNativeEnvironmentService:	get extensionsDownloadPath(): string {
		const cliExtensionsDownloadDir = this.args['extensions-download-dir'];
		if (cliExtensionsDownloadDir) {
			return resolve(cliExtensionsDownloadDir);
		}

		return join(this.userDataPath, 'CachedExtensionVSIXs');
	}