isCryptoCurrency function

bool isCryptoCurrency(
  1. String currencyId

Basically it doesn't really check if the currencyId is a crypto currency. It just checks if it's not fiat. I decided not to collect all possible crypto currecies as there's an endless amount of them


bool isCryptoCurrency(String currencyId) {
  if (currencyId.length < 3 || currencyId.length > 4) {
    return false;
  return !isFiatCurrency(currencyId);