Block.php

<?php

namespace Drupal\Core\Block\Annotation;

use Drupal\Component\Annotation\Plugin;

/**
 * Defines a Block annotation object.
 *
 * @ingroup block_api
 *
 * @Annotation
 */
class Block extends Plugin {
    
    /**
     * The plugin ID.
     *
     * @var string
     */
    public $id;
    
    /**
     * The administrative label of the block.
     *
     * @var \Drupal\Core\Annotation\Translation
     *
     * @ingroup plugin_translatable
     */
    public $admin_label = '';
    
    /**
     * The category in the admin UI where the block will be listed.
     *
     * @var \Drupal\Core\Annotation\Translation
     *
     * @ingroup plugin_translatable
     */
    public $category = '';
    
    /**
     * An array of context definitions describing the context used by the plugin.
     *
     * The array is keyed by context names.
     *
     * @var \Drupal\Core\Annotation\ContextDefinition[]
     */
    public $context_definitions = [];

}