ContentEntityType.php

<?php

namespace Drupal\Core\Entity\Annotation;

use Drupal\Core\StringTranslation\TranslatableMarkup;

/**
 * Defines a content entity type annotation object.
 *
 * Content Entity type plugins use an object-based annotation method, rather than an
 * array-type annotation method (as commonly used on other annotation types).
 * The annotation properties of content entity types are found on
 * \Drupal\Core\Entity\ContentEntityType and are accessed using
 * get/set methods defined in \Drupal\Core\Entity\ContentEntityTypeInterface.
 *
 * @ingroup entity_api
 *
 * @Annotation
 */
class ContentEntityType extends EntityType {
    
    /**
     * {@inheritdoc}
     */
    public $entity_type_class = 'Drupal\\Core\\Entity\\ContentEntityType';
    
    /**
     * {@inheritdoc}
     */
    public $group = 'content';
    
    /**
     * {@inheritdoc}
     */
    public function get() {
        $this->definition['group_label'] = new TranslatableMarkup('Content', [], [
            'context' => 'Entity type group',
        ]);
        return parent::get();
    }

}