test/test_hyperdbvals.py has

from mock import Mock

in the commit
changeset:   7212:76a21cf791b9

Where do I get this from?
My standard python 3.11.2 (debian stable aka bookworm) doesn't have it:

>>> from mock import Mock
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'mock'


But it seems to be in unittest:

>>> from unittest.mock import Mock
>>> 

But I'm unsure if this is the same thing.