code: @Bean
  	@Lazy
  	@ConditionalOnMissingBean(AbstractLoadBalancerAwareClient.class)
  	public RestClient ribbonRestClient(IClientConfig config, ILoadBalancer loadBalancer,
  			ServerIntrospector serverIntrospector, RetryHandler retryHandler) {
  		RestClient client = new RibbonClientConfiguration.OverrideRestClient(config,
  				serverIntrospector);
  		client.setLoadBalancer(loadBalancer);
  		client.setRetryHandler(retryHandler);
  		return client;
  	}
docs: Create a Netflix {@link RestClient} integrated with Ribbon if none already exists
  in the application context. It is not required for Ribbon to work properly and is
  therefore created lazily if ever another component requires it.
  @param config the configuration to use by the underlying Ribbon instance
  @param loadBalancer the load balancer to use by the underlying Ribbon instance
  @param serverIntrospector server introspector to use by the underlying Ribbon
  instance
  @param retryHandler retry handler to use by the underlying Ribbon instance
  @return a {@link RestClient} instances backed by Ribbon