Possible bug in RAG Tokenizer
On this line 
input_dict = tokenizer.prepare_seq2seq_batch(question, return_tensors="pt")
the following error is being generated 
AttributeError: 'super' object has no attribute 'prepare_seq2seq_batch'

hi @krishanudb 

Thank you for reporting this @krishanudb !<|||||>Is there any update on this issue? @patil-suraj <|||||>It's fixed now on master!
see #10167<|||||>The issue persists in transformers 4.3.3

/usr/local/lib/python3.7/dist-packages/transformers/models/rag/tokenization_rag.py in prepare_seq2seq_batch(self, src_texts, tgt_texts, max_length, max_target_length, **kwargs)
     75         if max_target_length is None:
     76             max_target_length = self.generator.model_max_length
---> 77         return super().prepare_seq2seq_batch(
     78             src_texts, tgt_texts, max_length=max_length, max_target_length=max_target_length, **kwargs
     79         )

AttributeError: 'super' object has no attribute 'prepare_seq2seq_batch'<|||||>Hi @rajasekar-venkatesan 

The issue is fixed on master after the `4.3.3` release.  This fix will be available in the next release.