public static void validateGroupInstanceId(String id) {
        Topic.validate(id, "Group instance id", message -> {
            throw new InvalidConfigurationException(message);
        });
    }
@Test
    public void shouldAcceptValidGroupInstanceIds() {
        String maxLengthString = TestUtils.randomString(249);
        String[] validGroupInstanceIds = {"valid", "INSTANCE", "gRoUp", "ar6", "VaL1d", "_0-9_.", "...", maxLengthString};

        for (String instanceId : validGroupInstanceIds) {
            JoinGroupRequest.validateGroupInstanceId(instanceId);
        }
    }