How to save checkpoint?

[yhcc]

From the tutorial, it shows to use save_checkpoint function to save state, but

ColossalAI/colossalai/utils/checkpointing.py

Lines 184 to 188 in 31fe842

	# if optimizer is not None:
	# checkpoint['optimizer'] = optimizer.state_dict()
	# if lr_scheduler is not None:
	# checkpoint['lr_scheduler'] = lr_scheduler.state_dict()

the optimizer and scheduler are not saved. What is the right way to checkpoint so that I can resume training? Thx~