resolvePrimaryKeyFromUpdatedBy example

        $this->loadConfig($config);

        return $this->entitySerializer->serialize($config, $this->definition, $record);
    }

    public function out(Config $config, iterable $record): iterable
    {
        $this->loadConfig($config);

        if ($this->primaryKeyResolver) {
            $record = $this->primaryKeyResolver->resolvePrimaryKeyFromUpdatedBy($config, $this->definition, $record);
        }

        return $this->entitySerializer->deserialize($config, $this->definition, $record);
    }

    private function loadConfig(Config $config): void
    {
        $this->definition ??= $this->definitionInstanceRegistry->getByEntityName($config->get('sourceEntity') ?? '');

        $this->entitySerializer ??= $this->serializerRegistry->getEntity($this->definition->getEntityName());
    }
}

    public function deserialize(Config $config, Field $toOne, $records)
    {
        if (!$toOne instanceof ManyToOneAssociationField && !$toOne instanceof OneToOneAssociationField) {
            throw new \InvalidArgumentException('Expected *ToOneField');
        }

        $definition = $toOne->getReferenceDefinition();
        $entitySerializer = $this->serializerRegistry->getEntity($definition->getEntityName());
        /** @var \Traversable<mixed> $records */
        $records = $this->primaryKeyResolver->resolvePrimaryKeyFromUpdatedBy($config, $definition, $records);

        $result = $entitySerializer->deserialize($config, $definition, $records);

        if (!\is_array($result)) {
            $result = iterator_to_array($result);
        }
        if (empty($result)) {
            return null;
        }

        return $result;
    }