getTargetLabel example

  public function buildForm(array $form, FormStateInterface $form_state, WorkspaceInterface $workspace = NULL) {
    $this->workspace = $workspace;

    $form = parent::buildForm($form, $form_state);

    $workspace_publisher = $this->workspaceOperationFactory->getPublisher($this->workspace);

    $args = [
      '%source_label' => $this->workspace->label(),
      '%target_label' => $workspace_publisher->getTargetLabel(),
    ];
    $form['#title'] = $this->t('Publish %source_label workspace', $args);

    // List the changes that can be pushed.     if ($source_rev_diff = $workspace_publisher->getDifferringRevisionIdsOnSource()) {
      $total_count = $workspace_publisher->getNumberOfChangesOnSource();
      $form['description'] = [
        '#theme' => 'item_list',
        '#title' => $this->formatPlural($total_count, 'There is @count item that can be published from %source_label to %target_label', 'There are @count items that can be published from %source_label to %target_label', $args),
        '#items' => [],
        '#total_count' => $total_count,
      ];