src/vs/platform/userDataSync/common/userDataSyncStoreService.ts/UserDataSyncStoreManagementService/constructor
class UserDataSyncStoreManagementService:	constructor(
		@IProductService productService: IProductService,
		@IConfigurationService configurationService: IConfigurationService,
		@IStorageService storageService: IStorageService,
	) {
		super(productService, configurationService, storageService);

		const previousConfigurationSyncStore = this.storageService.get(SYNC_PREVIOUS_STORE, StorageScope.GLOBAL);
		if (previousConfigurationSyncStore) {
			this.previousConfigurationSyncStore = JSON.parse(previousConfigurationSyncStore);
		}

		const syncStore = this.productService[CONFIGURATION_SYNC_STORE_KEY];
		if (syncStore) {
			this.storageService.store(SYNC_PREVIOUS_STORE, JSON.stringify(syncStore), StorageScope.GLOBAL, StorageTarget.MACHINE);
		} else {
			this.storageService.remove(SYNC_PREVIOUS_STORE, StorageScope.GLOBAL);
		}
	}