diff --git a/nvflare/app_opt/tf/fedopt_ctl.py b/nvflare/app_opt/tf/fedopt_ctl.py
index 45ca4c50c0..b04ac9af28 100644
--- a/nvflare/app_opt/tf/fedopt_ctl.py
+++ b/nvflare/app_opt/tf/fedopt_ctl.py
@@ -118,6 +118,7 @@ def update_model(self, global_model: FLModel, aggr_result: FLModel):
         specific set of Variables.
 
         """
+        # Get the Keras model stored in memory in persistor.
         global_model_tf = self.persistor.model
         global_params = global_model_tf.trainable_weights
         num_trainable_weights = len(global_params)