src/Executor/ReferenceExecutor.php
private function invalidReturnTypeError(
        ObjectType $returnType,
        $result,
        $fieldNodes
    ) {
        return new Error(
            'Expected value of type "' . $returnType->name . '" but got: ' . Utils::printSafe($result) . '.',
            $fieldNodes
        );
    }
private function invalidReturnTypeError(
        ObjectType $returnType,
        $result,
        $fieldNodes
    ) {
        return new Error(
            'Expected value of type "' . $returnType->name . '" but got: ' . Utils::printSafe($result) . '.',
            $fieldNodes
        );
    }
@param mixed[]     $result
@param FieldNode[] $fieldNodes

@return Error