diff --git a/xds/src/main/java/io/grpc/xds/XdsServerWrapper.java b/xds/src/main/java/io/grpc/xds/XdsServerWrapper.java
index a934dfde2f0..56f673fba62 100644
--- a/xds/src/main/java/io/grpc/xds/XdsServerWrapper.java
+++ b/xds/src/main/java/io/grpc/xds/XdsServerWrapper.java
@@ -116,8 +116,12 @@ public void uncaughtException(Thread t, Throwable e) {
   private volatile Server delegate;
 
   // Must be updated in the sync context.
-  // TODO(sergiitk): [QUESTION] should this be per filter chain too?
+  // TODO(sergiitk): [QUESTION] consider the implication of filterchain equality, during updates.
+  // how to identify this is the same filter chain
+  // - based on index?
+  // - based on FilterChainMatch?
   private final HashMap<String, Filter> activeFilters = new HashMap<>();
+  // private final HashMap<FilterChain, HashMap<String, Filter>> activeFilters = new HashMap<>();
 
   XdsServerWrapper(
       String listenerAddress,