keyvalue_test.module

<?php


/**
 * @file
 * Sets up the key value entity storage.
 */

/**
 * Implements hook_entity_type_alter().
 */
function keyvalue_test_entity_type_alter(array &$entity_types) {
    
    /** @var \Drupal\Core\Entity\EntityTypeInterface[] $entity_types */
    if (isset($entity_types['entity_test_label'])) {
        $entity_types['entity_test_label']->setStorageClass('Drupal\\Core\\Entity\\KeyValueStore\\KeyValueContentEntityStorage');
        $entity_keys = $entity_types['entity_test_label']->getKeys();
        $entity_types['entity_test_label']->set('entity_keys', $entity_keys + [
            'uuid' => 'uuid',
        ]);
        $entity_types['entity_test_label']->set('provider', 'keyvalue_test');
    }
}