Hi, I want to train a model using the trainer class in Transformers and want to manage the training process per epoch. Specifically, I want to do some calculations after one epoch. I find that the Callback class fits me well, as it has on_epoch_end and on_epoch_begin methods that support performing some operations before or after one epoch. However, the default inputs to the methods are limited, and I need some attributes in the trainer to perform calculations. Is there any way that allows me to access trainer attributes in the Callback class?