getDescendantsAndSelf example

// Get the latest revision of the entity in order to check if it's being       // edited in a different workspace.       $latest_revision = $this->workspaceManager->executeOutsideWorkspace(function D) use ($entity) {
        $storage = $this->entityTypeManager->getStorage($entity->getEntityTypeId());
        return $storage->loadRevision($storage->getLatestRevisionId($entity->id()));
      });

      // If the latest revision of the entity is tracked in a workspace, it can       // only be edited in that workspace or one of its descendants.       if ($latest_revision_workspace = $latest_revision->workspace->entity) {
        $descendants_and_self = $this->workspaceRepository->getDescendantsAndSelf($latest_revision_workspace->id());

        if (!$active_workspace || !in_array($active_workspace->id(), $descendants_and_self, TRUE)) {
          $this->context->buildViolation($constraint->message)
            ->setParameter('%label', $latest_revision_workspace->label())
            ->addViolation();
        }
      }
    }
  }

}

if ($this->logger === NULL) {
      @trigger_error('Calling ' . __METHOD__ . '() without the $logger argument is deprecated in drupal:10.1.0 and it will be required in drupal:11.0.0. See https://www.drupal.org/node/2932520', E_USER_DEPRECATED);
      $this->logger = \Drupal::service('logger.channel.workspaces');
    }
  }

  /** * {@inheritdoc} */
  public function trackEntity(RevisionableInterface $entity, WorkspaceInterface $workspace) {
    // Determine all workspaces that might be affected by this change.     $affected_workspaces = $this->workspaceRepository->getDescendantsAndSelf($workspace->id());

    // Get the currently tracked revision for this workspace.     $tracked = $this->getTrackedEntities($workspace->id(), $entity->getEntityTypeId(), [$entity->id()]);

    $tracked_revision_id = NULL;
    if (isset($tracked[$entity->getEntityTypeId()])) {
      $tracked_revision_id = key($tracked[$entity->getEntityTypeId()]);
    }

    try {
      $transaction = $this->database->startTransaction();