It's normal to try: ```python labels = torch.arange(32) x = lmu.get_all_pairs_indices(labels, ref_labels=labels) ``` This will result in 0 positive pairs because of the `labels is ref_labels` check. This isn't documented anywhere though. See https://github.com/KevinMusgrave/pytorch-metric-learning/discussions/495