skipping the padding message

[mojtaba-komeili]

Patch description
The rag agent may crash if there is batch padding message. These message do not contain the text data that it want to encode.

Test
It used to crash if it was receiving a batch padding message. It successfully finishes with this.

[stephenroller]

Use obs.is_padding_example()

[stephenroller]

Is observation not a message already?! This is doing a shallow copy which is fine, but we should have gotten those dicts out of there by now :(

[mojtaba-komeili]

Is observation not a message already?! This is doing a shallow copy which is fine, but we should have gotten those dicts out of there by now :(

It might be in the code that uses it. But since the params were allowing dict type as well I thought of doing that for safety.

[klshuster]

observation can be a dict but TorchAgent.observe takes care of that so this copy is probably not necessary but alas (self._generation_agent.observe() is guaranteed to return a Message)

[stephenroller]

I tried to make the teachers also forcefully output Messages by now

[klshuster]

interestingly the WoW teachers do not, which is probably where this error surfaced