ds-8.x-3.9/src/Plugin/DsField/Block/BlockTitle.php

<?php

namespace Drupal\ds\Plugin\DsField\Block;

use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\ds\Attribute\DsField;
use Drupal\ds\Plugin\DsField\Title;

/**
 * Plugin that renders the title of a block.
 */
#[DsField(
  id: 'block_title',
  title: new TranslatableMarkup('Title'),
  entity_type: 'block_content',
  provider: 'block_content'
)]
class BlockTitle extends Title {

  /**
   * {@inheritdoc}
   */
  public function entityRenderKey() {
    return 'info';
  }

}