Account debitedAccount = accountDao.findOne(debitedAccountId);
notNull(debitedAccount, "account with number {} not found", debitedAccount);
if (debitedAccount.getBalance().compareTo(amount) < 0) {
throw new UnsufficientBalanceException();
}
Account creditedAccount = accountDao.findOne(creditedAccountId);
notNull(creditedAccount, "account with number {} not found", creditedAccount);