trait AssertFileUsageTrait in Helper 8

trait AssertFileUsageTrait {

  /**
   * Assert file usage.
   *
   * @param int $expectedUsage
   *   The expected usage count.
   * @param int $fid
   *   The file ID to check for usage.
   * @param string $module
   *   The module to check for usage.
   * @param \Drupal\Core\Entity\EntityInterface $entity
   *   The attached entity to check for usage.
   */
  protected function assertFileUsage($expectedUsage, $fid, $module, EntityInterface $entity) {
    $file = File::load($fid);
    $usage = \Drupal::service('file.usage')
      ->listUsage($file);
    $usage = isset($usage[$module][$entity
      ->getEntityTypeId()][$entity
      ->id()]) ? $usage[$module][$entity
      ->getEntityTypeId()][$entity
      ->id()] : 0;
    $this
      ->assertEquals($expectedUsage, $usage);
  }

}