src/vs/platform/userDataSync/common/settingsSync.ts/isSyncData
function isSyncData(thing: any): thing is ISyncData {
	if (thing
		&& (thing.version !== undefined && typeof thing.version === 'number')
		&& (thing.content !== undefined && typeof thing.content === 'string')
		&& (thing.machineId !== undefined && typeof thing.machineId === 'string')
	) {
		return true;
	}

	return false;
}