Hi,

in Run_gqn.py I get an error on this line:
handler=checkpoint_handler, to_save={'model': model.state_dict, 'optimizer': optimizer.state_dict, 'annealers': (sigma_scheme.data, mu_scheme.data)})
Traceback (most recent call last):
File "../run-gqn.py", line 181, in
trainer.run(train_loader, args.n_epochs)
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 892, in run
return self._internal_run()
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 935, in _internal_run
return next(self._internal_run_generator)
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 993, in _internal_run_as_gen
self._handle_exception(e)
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 636, in _handle_exception
self._fire_event(Events.EXCEPTION_RAISED, e)
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 425, in _fire_event
func(*first, *(event_args + others), **kwargs)
File "../run-gqn.py", line 179, in handle_exception
else: raise e
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 965, in _internal_run_as_gen
self._fire_event(Events.EPOCH_COMPLETED)
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 425, in _fire_event
func(*first, *(event_args + others), **kwargs)
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/handlers/checkpoint.py", line 1037, in call
self._check_objects(to_save, "state_dict")
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/handlers/checkpoint.py", line 544, in _check_objects
raise TypeError(f"Object {type(obj)} should have {attr} method")
TypeError: Object <class 'method'> should have state_dict method

and if I change it to:
trainer.add_event_handler(event_name=Events.EPOCH_COMPLETED, handler=checkpoint_handler, to_save={'model': model, 'optimizer': optimizer, 'annealers': (sigma_scheme, mu_scheme)})
I get this error:
Traceback (most recent call last):
File "../run-gqn.py", line 181, in
trainer.run(train_loader, args.n_epochs)
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 892, in run
return self._internal_run()
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 935, in _internal_run
return next(self._internal_run_generator)
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 993, in _internal_run_as_gen
self._handle_exception(e)
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 636, in _handle_exception
self._fire_event(Events.EXCEPTION_RAISED, e)
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 425, in _fire_event
func(*first, *(event_args + others), **kwargs)
File "../run-gqn.py", line 179, in handle_exception
else: raise e
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 965, in _internal_run_as_gen
self._fire_event(Events.EPOCH_COMPLETED)
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/engine/engine.py", line 425, in _fire_event
func(*first, *(event_args + others), **kwargs)
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/handlers/checkpoint.py", line 1037, in call
self._check_objects(to_save, "state_dict")
File "/home/ssl/miniconda3/envs/cuda/lib/python3.7/site-packages/ignite/handlers/checkpoint.py", line 544, in _check_objects
raise TypeError(f"Object {type(obj)} should have {attr} method")
TypeError: Object <class 'tuple'> should have state_dict method

any solution?