Masking in T5Attention
@patil-suraj    @patrickvonplaten    Hello! I was wondering why have you added mask in T5Attention to position_bias????? look at 
https://github.com/huggingface/transformers/blob/db7d6a80e82d66127b2a44b6e3382969fdc8b207/src/transformers/models/t5/modeling_t5.py#L510
Hey, 

I think simply corresponds to how it is done in the original implementation. It essentially means that we don't add any **positional** information for tokens that are masked.<|||||>ok understand thanks!