src/vs/platform/extensionManagement/common/extensionStorage.ts/ExtensionStorageService/readAllExtensionsWithKeysForSync
class ExtensionStorageService:	private static readAllExtensionsWithKeysForSync(storageService: IStorageService): Map<string, string[]> {
		const extensionsWithKeysForSync = new Map<string, string[]>();
		const keys = storageService.keys(StorageScope.PROFILE, StorageTarget.MACHINE);
		for (const key of keys) {
			const extensionIdWithVersion = ExtensionStorageService.fromKey(key);
			if (extensionIdWithVersion) {
				let versions = extensionsWithKeysForSync.get(extensionIdWithVersion.id.toLowerCase());
				if (!versions) {
					extensionsWithKeysForSync.set(extensionIdWithVersion.id.toLowerCase(), versions = []);
				}
				versions.push(extensionIdWithVersion.version);
			}
		}
		return extensionsWithKeysForSync;
	}