# public getBalansCreditAmount to get the amount of all accounts
sub getBalansCreditAmount {
    my $closure = shift;
    my $totalCreditAmount = $closure->getCreditAmount();
    for my $balans ( $closure->getCreditAccounts() ) {
        $totalCreditAmount += $balans->getBalansCreditAmount();
    }
    return $totalCreditAmount;
}