forward_without_verbalize

[vickywu1022]

When doing prompt-learning without any verbalizer, I used forward_without_verbalize and encountered an error:

Traceback (most recent call last):
File "~/OpenPrompt/openprompt/pipeline_base.py", line 309, in forward_without_verbalize
    outputs = self.verbalizer.gather_outputs(outputs)
AttributeError: 'NoneType' object has no attribute 'gather_outputs'

I think there is no need for such gathering since we use no verbalizer here:)