src/vs/platform/userDataSync/common/abstractSynchronizer.ts/AbstractSynchroniser/updateRemoteUserData
class AbstractSynchroniser:	protected async updateRemoteUserData(content: string, ref: string | null): Promise<IRemoteUserData> {
		const machineId = await this.currentMachineIdPromise;
		const syncData: ISyncData = { version: this.version, machineId, content };
		try {
			ref = await this.userDataSyncStoreService.writeResource(this.resource, JSON.stringify(syncData), ref, this.collection, this.syncHeaders);
			return { ref, syncData };
		} catch (error) {
			if (error instanceof UserDataSyncError && error.code === UserDataSyncErrorCode.TooLarge) {
				error = new UserDataSyncError(error.message, error.code, this.resource);
			}
			throw error;
		}
	}