Hi, I am also interested in topic and I am trying to add mBart functionality to another library, but I have encountered strange error: https://huggingface.co/transformers/model_doc/mbart.html 2 states that prepare_seq2seq_batch should give me dict with this keys: [input_ids, attention_mask, decoder_input_ids,  decoder_attention_mask], but actually it gives me [input_ids, attention_mask, labels]. I am a bit confused 
Is it a bug or me doing something wrong?