NameError: name 'rand_pad' is not defined

Hi all,
I have a question regarding rand_pad.
I am trying to use rand_pad but I get error: name ‘rand_pad’ is not defined
Before that I have imported everything with:
from fastai.vision.all import *

I am using fastai version 2.1.0. and Python version 3.6.9

Thank you for your help!