I'm not sure it is needed indeed.
It was to be on the safe side (since only the loader-git seems strike by this...)

I checked the storage's model, it's indeed a string so that should fairly be always a string.

oh yeah, i remember that now!

This will always be True. Double underscore attributes get a mangled name.

In [1]: class Foo:
   ...:     def __init__(self):
   ...:         self.__bla = None
   ...:         

In [2]: foo = Foo()

In [3]: foo.__dict__
Out[3]: {'_Foo__bla': None}

In [4]: hasattr(foo, '__bla')
Out[4]: False

I'm not sure what you're really asserting here?

This is a private attribute. It won't be accessed by another other class and this one is empty.

yeah please, don't use 'private' attributes, like ever. This mangling magic stuff is nothing but garbage...

At the time, it was to make the test pass as this would not otherwise.
I'm currently trying to assert the removal somehow works now.

As it works without those, removed! I must have mis-analyzed the issue at the time.
Thanks for the heads up.