<kotlin null safe container' is a mutable property...

# stackoverflow

[user]

kotlin null safe container' is a mutable property that could have been changed by this time
class ExchangeRatesServiceImpl : ExchangeRatesService {

private var container: ExchangeRatesContainer? = null

/**
* {@inheritDoc}
*/
override val currentRates: Map
get() {
if (container == null || container.date != LocalDate.now()) {
container = client.getRates(Currency.getBase())
log.info("exchange rates has been updated: {}", container)
}
return ImmutableMap.of(
Currency.EUR, container.rates[Currency.EUR.name],...