diff --git a/nvflare/app_opt/tf/fedopt_ctl.py b/nvflare/app_opt/tf/fedopt_ctl.py
index 7bfd051e8c..45ca4c50c0 100644
--- a/nvflare/app_opt/tf/fedopt_ctl.py
+++ b/nvflare/app_opt/tf/fedopt_ctl.py
@@ -106,69 +106,69 @@ def _to_tf_params_list(self, params: Dict, negate: bool = False):
             tf_params_list.append(tf.Variable(v))
         return tf_params_list
 
-        def update_model(self, global_model: FLModel, aggr_result: FLModel):
-            """
-            Override the default version of update_model
-            to perform update with Keras Optimizer on the
-            global model stored in memory in persistor, instead of
-            creating new temporary model on-the-fly.
-
-            Creating a new model would not work for Keras
-            Optimizers, since an optimizer is bind to
-            specific set of Variables.
-
-            """
-            global_model_tf = self.persistor.model
-            global_params = global_model_tf.trainable_weights
-            num_trainable_weights = len(global_params)
-
-            model_diff_params = {}
-
-            w_idx = 0
-
-            for key, param in global_model.params.items():
-                if w_idx >= num_trainable_weights:
-                    break
-
-                if param.shape == global_params[w_idx].shape:
-                    model_diff_params[key] = (
-                        aggr_result.params[key] - param
-                        if aggr_result.params_type == ParamsType.FULL
-                        else aggr_result.params[key]
-                    )
-                    w_idx += 1
+    def update_model(self, global_model: FLModel, aggr_result: FLModel):
+        """
+        Override the default version of update_model
+        to perform update with Keras Optimizer on the
+        global model stored in memory in persistor, instead of
+        creating new temporary model on-the-fly.
 
-            model_diff = self._to_tf_params_list(model_diff_params, negate=True)
-            start = time.time()
+        Creating a new model would not work for Keras
+        Optimizers, since an optimizer is bind to
+        specific set of Variables.
 
-            self.optimizer.apply_gradients(zip(model_diff, global_params))
-            secs = time.time() - start
+        """
+        global_model_tf = self.persistor.model
+        global_params = global_model_tf.trainable_weights
+        num_trainable_weights = len(global_params)
 
-            start = time.time()
-            weights = global_model_tf.get_weights()
+        model_diff_params = {}
 
-            new_weights = {}
-            for w_idx, key in enumerate(global_model.params):
-                if key in model_diff_params:
-                    new_weights[key] = weights[w_idx]
+        w_idx = 0
 
-                else:
+        for key, param in global_model.params.items():
+            if w_idx >= num_trainable_weights:
+                break
 
-                    new_weights[key] = (
-                        aggr_result.params[key]
-                        if aggr_result.params_type == ParamsType.FULL
-                        else global_model.params[key] + aggr_result.params[key]
+            if param.shape == global_params[w_idx].shape:
+                model_diff_params[key] = (
+                    aggr_result.params[key] - param
+                    if aggr_result.params_type == ParamsType.FULL
+                    else aggr_result.params[key]
                     )
-            secs_detach = time.time() - start
-            self.info(
-                f"FedOpt ({type(self.optimizer)}) server model update "
-                f"round {self.current_round}, "
-                f"{type(self.lr_scheduler)} "
-                f"lr: {self.optimizer.learning_rate(self.optimizer.iterations).numpy()}, "
-                f"update: {secs} secs., detach: {secs_detach} secs.",
-            )
-
-            global_model.params = new_weights
-            global_model.meta = aggr_result.meta
-
-            return global_model
+                w_idx += 1
+
+        model_diff = self._to_tf_params_list(model_diff_params, negate=True)
+        start = time.time()
+
+        self.optimizer.apply_gradients(zip(model_diff, global_params))
+        secs = time.time() - start
+
+        start = time.time()
+        weights = global_model_tf.get_weights()
+
+        new_weights = {}
+        for w_idx, key in enumerate(global_model.params):
+            if key in model_diff_params:
+                new_weights[key] = weights[w_idx]
+
+            else:
+
+                new_weights[key] = (
+                    aggr_result.params[key]
+                    if aggr_result.params_type == ParamsType.FULL
+                    else global_model.params[key] + aggr_result.params[key]
+                )
+        secs_detach = time.time() - start
+        self.info(
+            f"FedOpt ({type(self.optimizer)}) server model update "
+            f"round {self.current_round}, "
+            f"{type(self.lr_scheduler)} "
+            f"lr: {self.optimizer.learning_rate(self.optimizer.iterations).numpy()}, "
+            f"update: {secs} secs., detach: {secs_detach} secs.",
+        )
+
+        global_model.params = new_weights
+        global_model.meta = aggr_result.meta
+
+        return global_model