added todo

spring-cloud-netflix-hystrix-stream/src/main/java/org/springframework/cloud/netflix/hystrix/stream/HystrixStreamTask.java

@@ -68,6 +68,7 @@ public class HystrixStreamTask implements ApplicationContextAware {
 	private HystrixStreamProperties properties;
 
 	// Visible for testing
+	// TODO: configurable size.
 	final LinkedBlockingQueue<String> jsonMetrics = new LinkedBlockingQueue<>(
 			1000);