src/vs/platform/userDataSync/common/extensionsSync.ts/ExtensionsSynchroniser/stringify
class ExtensionsSynchroniser:	private stringify(extensions: ISyncExtension[], format: boolean): string {
		extensions.sort((e1, e2) => {
			if (!e1.identifier.uuid && e2.identifier.uuid) {
				return -1;
			}
			if (e1.identifier.uuid && !e2.identifier.uuid) {
				return 1;
			}
			return compare(e1.identifier.id, e2.identifier.id);
		});
		return format ? toFormattedString(extensions, {}) : JSON.stringify(extensions);
	}