public Currency search(String string) throws CurrencyNotFoundException, MultipleCurrencyException {
        for (Currency currency : set) {
            if (currency.getCode().equalsIgnoreCase(string)) return currency;
            if (currency.getSymbol().equalsIgnoreCase(string)) return currency;
            if (currency.getName().equalsIgnoreCase(string)) return currency;
            if (currency.getName().toLowerCase().contains(string.toLowerCase())) {
                Currency[] list = currencyList(string);
                if (list.length == 1) {
                    return list[0];
                } else {
                    throw new MultipleCurrencyException(currency.getName().toLowerCase());
                }
            }
        }
        throw new CurrencyNotFoundException("Error: Currency not found");
    }