code: public void unregisterService(String serviceName, String providerAddress) {
          getServiceDirectoryClient().unregisterInstance(serviceName, providerAddress, disableOwnerError);
      }
docs: Unregister a ProvidedServiceInstance
  The ProvidedServiceInstance is uniquely identified by serviceName and providerAddress
  
  @param serviceName
  the serviceName of ProvidedServiceInstance.
  @param providerAddress
  the provierAddress of ProvidedServiceInstance.