docs: @Override
      public ServiceInstance getInstanceByAddress(String serviceName, String instanceAddress)
              throws ServiceException {
  
          ServiceInstanceUtils.validateManagerIsStarted(isStarted.get());
          ServiceInstanceUtils.validateServiceName(serviceName);
          ServiceInstanceUtils.validateAddress(instanceAddress);
  
          ModelServiceInstance instance = getLookupService().getModelServiceInstanceByAddress(serviceName, instanceAddress);
  
          if (instance!=null) {
              return ServiceInstanceUtils.toServiceInstance(instance);
          }
          return null;
      }