code: public static ILoadBalancer registerNamedLoadBalancerFromclientConfig(String name, IClientConfig clientConfig) throws ClientException {
          if (namedLBMap.get(name) != null) {
              throw new ClientException("LoadBalancer for name " + name + " already exists");
          }
      	ILoadBalancer lb = null;
          try {
              String loadBalancerClassName = clientConfig.getOrDefault(CommonClientConfigKey.NFLoadBalancerClassName);
              lb = (ILoadBalancer) ClientFactory.instantiateInstanceWithClientConfig(loadBalancerClassName, clientConfig);                                    
              namedLBMap.put(name, lb);            
              logger.info("Client: {} instantiated a LoadBalancer: {}", name, lb);
              return lb;
          } catch (Throwable e) {           
             throw new ClientException("Unable to instantiate/associate LoadBalancer with Client:" + name, e);
          }    	
      }
docs: Create and register a load balancer with the name and given the class of configClass.
  
  @throws ClientException if load balancer with the same name already exists or any error occurs
  @see #instantiateInstanceWithClientConfig(String, IClientConfig)