Youshido\GraphQL\Validator\ConfigValidator\ConfigValidator::getInstance PHP Метод

    public static function getInstance()
    {
        if (empty(self::$instance)) {
            self::$instance = new self();
        }
        self::$instance->clearErrors();
        return self::$instance;
    }

 public function validate()
 {
     $validator = ConfigValidator::getInstance();
     if (!$validator->validate($this->data, $this->getContextRules(), $this->extraFieldsAllowed)) {
         throw new ConfigurationException('Config is not valid for ' . ($this->contextObject ? get_class($this->contextObject) : null) . "\n" . implode("\n", $validator->getErrorsArray(false)));
     }
 }