WorkspacePublishException example

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 publish() {
    if ($this->sourceWorkspace->hasParent()) {
      throw new WorkspacePublishException('Only top-level workspaces can be published.');
    }

    if ($this->checkConflictsOnTarget()) {
      throw new WorkspaceConflictException();
    }

    $tracked_entities = $this->workspaceAssociation->getTrackedEntities($this->sourceWorkspace->id());
    $event = new WorkspacePrePublishEvent($this->sourceWorkspace, $tracked_entities);
    $this->eventDispatcher->dispatch($event);

    if ($event->isPublishingStopped()) {