public function getData()
 {
     $this->validate('transactionReference');
     $data = parent::getData();
     $data['sale_id'] = $this->getTransactionReference();
     return $data;
 }
 public function getData()
 {
     // An amount parameter is required, as is a currency and
     // an account ID.
     $this->validate('transactionReference');
     $data = parent::getData();
     $data['sale_id'] = $this->getTransactionReference();
     return $data;
 }