Update trainer.py

Author: ananthsub

pytorch_lightning/trainer/trainer.py

@@ -1211,6 +1211,13 @@ def _cache_logged_metrics(self):
             self.logger_connector.cache_logged_metrics()
 
     def call_hook(self, hook_name: str, *args, **kwargs) -> Any:
+        # Note this implementation is copy/pasted into the TrainLoop class
+        # in TrainLoop._on_train_epoch_end_hook
+        # This was done to manage the deprecation of an argument to
+        # on_train_epoch_end
+        # If making chnages to this function, ensure that those changes are also made to
+        # TrainLoop._on_train_epoch_end_hook
+
         # set hook_name to model + reset Result obj
         skip = self._reset_result_and_set_hook_fx_name(hook_name)