ignite: ValueError: Object should have `state_dict` method.

hi，when I train your reid_baseline model ,I met a error that I can’t solve. the error is as follows:

Traceback (most recent call last): File “/home/lc/Desktop/reid_baseline/tools/train.py”, line 87, in <module> main() File “/home/lc/Desktop/reid_baseline/tools/train.py”, line 83, in main train(cfg) File “/home/lc/Desktop/reid_baseline/tools/train.py”, line 46, in train num_query File “/home/lc/Desktop/reid_baseline/engine/trainer.py”, line 150, in do_train trainer.run(train_loader, max_epochs=epochs) File “/usr/local/lib/python3.5/dist-packages/pytorch_ignite-0.2.0-py3.5.egg/ignite/engine/engine.py”, line 388, in run File “/usr/local/lib/python3.5/dist-packages/pytorch_ignite-0.2.0-py3.5.egg/ignite/engine/engine.py”, line 352, in _handle_exception File “/usr/local/lib/python3.5/dist-packages/pytorch_ignite-0.2.0-py3.5.egg/ignite/engine/engine.py”, line 379, in run File “/usr/local/lib/python3.5/dist-packages/pytorch_ignite-0.2.0-py3.5.egg/ignite/engine/engine.py”, line 287, in _fire_event File “/usr/local/lib/python3.5/dist-packages/pytorch_ignite-0.2.0-py3.5.egg/ignite/handlers/checkpoint.py”, line 172, in call File “/usr/local/lib/python3.5/dist-packages/pytorch_ignite-0.2.0-py3.5.egg/ignite/handlers/checkpoint.py”, line 130, in _save File “/usr/local/lib/python3.5/dist-packages/pytorch_ignite-0.2.0-py3.5.egg/ignite/handlers/checkpoint.py”, line 144, in _internal_save ValueError: Object should have state_dict method.

How should I fix it?