protected function assertDocumentValidator($queryString, $max, array $expectedErrors = [])
 {
     $errors = DocumentValidator::validate(QuerySecuritySchema::buildSchema(), Parser::parse($queryString), [$this->getRule($max)]);
     $this->assertEquals($expectedErrors, array_map(['GraphQL\\Error\\Error', 'formatError'], $errors), $queryString);
     return $errors;
 }