How to get more than just the best prediction from compute_predictions_logits()?

I’m developing a Q&A app where I would like to show the user not only the best answer but the top 3 answers from the model. I’m using the compute_predictions_logits() method (transformers/ at master · huggingface/transformers · GitHub) and I set n_best_size=3 when calling the method. But the method only ever returns the best answer. What am I doing wrong?