@Override
		protected boolean hasError(HttpStatusCode statusCode) {
			/**
			 * When the Eureka server restarts and a client tries to send a heartbeat the
			 * server will respond with a 404. By default, RestTemplate will throw an
			 * exception in this case. What we want is to return the 404 to the upstream
			 * code, so it will send another registration request to the server.
			 */
			if (statusCode.is4xxClientError()) {
				return false;
			}
			return super.hasError(statusCode);
		}
@deprecated pass the default values while initialising object in test classes.
spring-cloud-netflix-eureka-client/src/main/java/org/springframework/cloud/netflix/eureka/http/RestTemplateTransportClientFactory.java