Custom dataset (Unpaired dataset)

Hello, i am trying to replicated my some of my code from PyTorch, in this code i have 2x dataloaders that i use zip to iterate through both at the same time, i want to do something simular in fastai, i have 2 folders one with photos, and one with human art illustrations, i my task i wannt to achive is to transfer the style from the photos to that of the illustrations. I want to do that in an unpaired mannor using a GAN but i cannot understand how i should write a dataset that after each epoch is randomized, or how each to label the data etc.