code: public function getClassProperties()
      {
          return [
              'reference' => $this->getReference(),
              'bank_name' => $this->getBankName(),
              'account_holder' => $this->getAccountHolder(),
              'iban' => $this->getIban(),
              'bic' => $this->getBic(),
              'amount' => $this->getAmount(),
              'due_date' => $this->getDueDate(),
          ];
      }
docs: {@inheritdoc}