public function getSchemaUniqueConstraints($conn = null)
    {
        $command = $this->invoke('neo.get_constraints_command', $conn);
        $httpResponse = $command->execute();

        $responseO = $this->handleHttpResponse($httpResponse);
        $response = $responseO->getBody();
        $constraints = [];
        foreach ($response as $constraint) {
            foreach ($constraint['property_keys'] as $key) {
                $constraints[] = new UniqueConstraint($constraint['label'], $key);
            }
        }

        return $constraints;
    }