how to use my custom trained model

[kyuhong0206]

i finetuned BiT-R50 and save like bit.pth.tar
torch.save({
"step": step,
"model": model.state_dict(),
"optim" : optim.state_dict(),
}, savename)

but i can't use it for test like
checkpoint = torch.load(f'/srv/data/datasets/kyuhong/big_transfer/bit_logs/products/bit.pth.tar')
self.model.load_state_dict(checkpoint['model'])

how can i use my custom trained model