fund-buying-transaction-create-command-handler.java

    @Override
    public FundTransaction handle(FundSellingTransactionCreate command) {
        Fund fund = fundDataPort.retrieve(command.getCode());
        Portfolio portfolio = portfolioDataPort.get(command.getUser(), command.getPortfolioId());

        // TODO read the reference currency from the account profile later.
        CurrencyCode referenceCurrencyCode = CurrencyCode.USD;

        CurrencyRetrieveRate currencyRetrieveRateCmd = buildCurrencyRetrieveRate(
                fund, referenceCurrencyCode, command);

        CurrencyRate referenceCurrencyRate = publish(CurrencyRate.class, currencyRetrieveRateCmd);

        return fundTransactionDataPort.createSellingTransaction(portfolio, fund, referenceCurrencyRate, command);
    }