updateEntityField example

$field_names = array_map([$resource_type, 'getInternalName'], array_merge(array_keys($data['attributes']), array_keys($data['relationships'])));

    // User resource objects contain a read-only attribute that is not a real     // field on the user entity type.     // @see \Drupal\jsonapi\JsonApiResource\ResourceObject::extractContentEntityFields()     // @todo: eliminate this special casing in https://www.drupal.org/project/drupal/issues/3079254.     if ($entity->getEntityTypeId() === 'user') {
      $field_names = array_diff($field_names, [$resource_type->getPublicName('display_name')]);
    }

    array_reduce($field_names, function DEntityInterface $destination, $field_name) use ($resource_type, $parsed_entity) {
      $this->updateEntityField($resource_type, $parsed_entity, $destination, $field_name);
      return $destination;
    }, $entity);

    static::validate($entity, $field_names);

    // Set revision data details for revisionable entities.     if ($entity->getEntityType()->isRevisionable()) {
      if ($bundle_entity_type = $entity->getEntityType()->getBundleEntityType()) {
        $bundle_entity = $this->entityTypeManager->getStorage($bundle_entity_type)->load($entity->bundle());
        if ($bundle_entity instanceof RevisionableEntityBundleInterface) {
          $entity->setNewRevision($bundle_entity->shouldCreateNewRevision());
        }