NLLB tokenizer multiple target/source languages within a training batch

Hi anyone has a solution to this?

To my understanding, one way to prepare the training data for finetuning if we feed the model the same sentence pair twice but flipped so that the model learns to translate in both direction.

Eg (LHS is the Input & RHS is the Target):

{"eng_Latn": "Hi", "zho_Hans": "你好"}
{"zho_Hans": "你好", "eng_Latn": "Hi"}

But I can’t seem to find a way to do this with the Trainer API.