Multiprocessing managers and custom classes

I do not know why, but I get this strange error whenever I try to pass to the method of a shared object shared custom class object. Python version: 3.6.3

Code:

from multiprocessing.managers import SyncManager

class MyManager(SyncManager): pass
class MyClass: pass

class Wrapper:
    def set(self, ent):
        self.ent = ent

MyManager.register('MyClass', MyClass)
MyManager.register('Wrapper', Wrapper)

if __name__ == '__main__':
    manager = MyManager()
    manager.start()

    try:
        obj = manager.MyClass()
        lst = manager.list([1,2,3])

        collection = manager.Wrapper()
        collection.set(lst) # executed fine
        collection.set(obj) # raises error
    except Exception as e:
        raise

Error:

---------------------------------------------------------------------------
Traceback (most recent call last):
  File "D:Program FilesPython363libmultiprocessingmanagers.py", line 228, in serve_client
    request = recv()
  File "D:Program FilesPython363libmultiprocessingconnection.py", line 251, in recv
    return _ForkingPickler.loads(buf.getbuffer())
  File "D:Program FilesPython363libmultiprocessingmanagers.py", line 881, in RebuildProxy
    return func(token, serializer, incref=incref, **kwds)
TypeError: AutoProxy() got an unexpected keyword argument 'manager_owned'
---------------------------------------------------------------------------

What’s the problem here?

Answer

Found temporary solution here. I’ve managed to fix it by adding needed keyword to initializer of AutoProxy in multiprocessingmanagers.py Though, I don’t know if this kwarg is responsible for anything.