Lack of code files for training reward classifier of Kuka stacking.

Hi, your work is wonderful. 

I would really like to train the diffusion model and reward classifier of the kuka stacking experiment for research use. The current code does not include the RewardMuJoCoDataset, Classifier, and RewardTrainer imported in the reward_classifier.py file. Could you please provide the files defining these classes?

Looking forward to your replay. Thanks a lot.