public static function isValidError(string $name, $node = null): ?ValidationException
    {
        if (\strlen($name) > 1 && $name{0} === '_' && $name{1} === '_') {
            return new ValidationException(
                sprintf('Name "%s" must not begin with "__", which is reserved by GraphQL introspection.', $name),
                $node instanceof NodeInterface ? [$node] : null
            );
        }

        if (preg_match("/^[_a-zA-Z][_a-zA-Z0-9]*$/", $name) === 0) {
            return new ValidationException(
                sprintf('Names must match /^[_a-zA-Z][_a-zA-Z0-9]*$/ but "%s" does not.', $name),
                $node instanceof NodeInterface ? [$node] : null
            );
        }

        return null;
    }