About "avoid" in beamsearch in predict.ipynb

[wai7niu8]

Hello @udibr , I'm confused about the parameter "avoid" in beamsearch and gensamples in predict.ipynb, and in train.ipynb, it doesn't exist. And, what role does the parameter "short" in gensamples play? And what's the role of "codes" in gensamples?
I'll appreciate it if you can answer the "simple" questions for me.