

TITLE
should be BartConfig.prefix  None?

COMMENTS
1

REACTIONS
+1: 0
-1: 0
laugh: 0
hooray: 0
heart: 0
rocket: 0
eyes: 0

BODY
For bart-large-xsum/bart-large-cnn, currently set to `' '`

+  does not help evaluation performance vs setting to `None` (checked xsum and CNN)

+ It could help fine-tuning performance by serving as a work-around for the `add_prefix_space` issue?
Putting here in case others have thoughts.

