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Co-authored-by: Ethan Harris <[email protected]>

pytorch_lightning/accelerator_backends/tpu_backend.py

@@ -118,7 +118,7 @@ def tpu_train_in_process(self, tpu_core_idx: int, model: LightningModule, traine
         # persist info in spawn
         trainer.transfer_distrib_spawn_state_on_fit_end(model, mp_queue, results)
 
-    def __save_end_of_training_weights(self, model: LightningModule, trainer=None):
+    def __save_end_of_training_weights(self, model: LightningModule, trainer):
         # when training ends on these platforms dump weights to get out of the main process
         if trainer.on_colab_kaggle:
             rank_zero_warn('cleaning up... please do not interrupt')