NormalizerBase.php

<?php

namespace Drupal\hal\Normalizer;

use Drupal\serialization\Normalizer\NormalizerBase as SerializationNormalizerBase;
use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;

/**
 * Base class for Normalizers.
 */
abstract class NormalizerBase extends SerializationNormalizerBase implements DenormalizerInterface {
  
  /**
   * {@inheritdoc}
   */
  protected $format = [
    'hal_json',
  ];

}