Form.php

<?php

namespace Drupal\Core\Render\Element;

use Drupal\Core\Render\Attribute\RenderElement;

/**
 * Provides a render element for a form.
 */
class Form extends RenderElementBase {
    
    /**
     * {@inheritdoc}
     */
    public function getInfo() {
        return [
            '#method' => 'post',
            '#theme_wrappers' => [
                'form',
            ],
        ];
    }

}