private InstanceEntity convertFromInstance(final Instance instance) {
        InstanceEntity instanceEntity = new InstanceEntity();
        instanceEntity.setPort(instance.getPort());
        instanceEntity.setHost(instance.getHost());
        instanceEntity.setAppName(instance.getService());
        instanceEntity.setUri(URI.create(String.format("%s://%s:%s", instance.getProtocol(), instance.getHost(), instance.getPort())));
        return instanceEntity;
    }
selectInstances.
@param selectKey selectKey
@return {@link List}
shenyu-registry/shenyu-registry-polaris/src/main/java/org/apache/shenyu/registry/polaris/PolarisInstanceRegisterRepository.java