vendor/symfony/config/Definition/Builder/ValidationBuilder.php line 34
<?php/** This file is part of the Symfony package.** (c) Fabien Potencier <fabien@symfony.com>** For the full copyright and license information, please view the LICENSE* file that was distributed with this source code.*/namespace Symfony\Component\Config\Definition\Builder;/*** This class builds validation conditions.** @author Christophe Coevoet <stof@notk.org>*/class ValidationBuilder{protected $node;public $rules = [];public function __construct(NodeDefinition $node){$this->node = $node;}/*** Registers a closure to run as normalization or an expression builder to build it if null is provided.** @return ExprBuilder|$this*/public function rule(\Closure $closure = null): ExprBuilder|static{if (null !== $closure) {$this->rules[] = $closure;return $this;}return $this->rules[] = new ExprBuilder($this->node);}}