Label.php

<?php

namespace Drupal\Core\Render\Element;

use Drupal\Core\Render\Attribute\RenderElement;

/**
 * Provides a render element for displaying the label for a form element.
 *
 * Labels are generated automatically from element properties during processing
 * of most form elements. This element is used internally by the form system
 * to render labels for form elements.
 */
class Label extends RenderElementBase {
    
    /**
     * {@inheritdoc}
     */
    public function getInfo() {
        return [
            '#theme' => 'form_element_label',
        ];
    }

}