diff --git a/spring-cloud-gateway-sample/src/main/java/org/springframework/cloud/gateway/sample/ThrottleWebFilterFactory.java b/spring-cloud-gateway-sample/src/main/java/org/springframework/cloud/gateway/sample/ThrottleWebFilterFactory.java
index dba50411..74e975b2 100644
--- a/spring-cloud-gateway-sample/src/main/java/org/springframework/cloud/gateway/sample/ThrottleWebFilterFactory.java
+++ b/spring-cloud-gateway-sample/src/main/java/org/springframework/cloud/gateway/sample/ThrottleWebFilterFactory.java
@@ -48,6 +48,7 @@ public class ThrottleWebFilterFactory implements WebFilterFactory {
 				.build();
 
 		return (exchange, chain) -> {
+			//TODO: get a token bucket for a key
 			log.debug("TokenBucket capacity: " + tokenBucket.getCapacity());
 			boolean consumed = tokenBucket.tryConsume();
 			if (consumed) {