Added TODO
diff --git a/test/cpp/end2end/client_lb_end2end_test.cc b/test/cpp/end2end/client_lb_end2end_test.cc
index 6e06b25..e582a0f 100644
--- a/test/cpp/end2end/client_lb_end2end_test.cc
+++ b/test/cpp/end2end/client_lb_end2end_test.cc
@@ -539,6 +539,8 @@
   EXPECT_EQ("round_robin", channel->GetLoadBalancingPolicyName());
 }
 
+// TODO(juanlishen): Investigate getting rid of threads once
+// https://github.com/grpc/grpc/pull/15841 is in.
 TEST_F(ClientLbEnd2endTest, RoundRobinProcessPending) {
   StartServers(1);  // Single server
   auto channel = BuildChannel("round_robin");