/**
  * {@inheritdoc}
  */
 protected function mapToStorageRecord(ContentEntityInterface $entity, $table_name = NULL)
 {
     /** @var \Drupal\payment\Entity\PaymentInterface $payment */
     $payment = $entity;
     $record = parent::mapToStorageRecord($entity, $table_name);
     $deltas = [];
     foreach ($payment->getPaymentStatuses() as $delta => $item) {
         $deltas[] = $delta;
     }
     $record->current_payment_status_delta = max($deltas);
     return $record;
 }