<Instance of Sub, address 43655008:
 _ListTree__visited={}
 data1=spam
 data2=eggs
 data3=42

....<Class Sub, address 43430248:
     __doc__
     __init__
     __module__
     __qualname__
     spam=<function tester.<locals>.Sub.spam at 0x000000000299A7B8>

........<Class Super, address 43429336:
         __dict__
         __doc__
         __init__
         __module__
         __qualname__
         __weakref__
         ham=<function tester.<locals>.Super.ham at 0x000000000299A6A8>

............<Class object, address 506770624:
             __class__
             __delattr__
             __dir__
             __doc__
             __eq__
             __format__
             __ge__
             __getattribute__
             __gt__
             __hash__
             __init__
             __le__
             __lt__
             __ne__
             __new__
             __reduce__
             __reduce_ex__
             __repr__
             __setattr__
             __sizeof__
             __str__
             __subclasshook__
............>
........>

........<Class ListTree, address 43428424:
         _ListTree__attrnames=<function ListTree.__attrnames at 0x000000000299A0D0>
         _ListTree__listclass=<function ListTree.__listclass at 0x000000000299A158>
         __dict__
         __doc__
         __module__
         __qualname__
         __str__
         __weakref__

............<Class object:, address 506770624: (see above)>
........>
....>
>
