1# Reference cycles involving only the ob_type field are rather uncommon
2# but possible.  Inspired by SF bug 1469629.
3
4import gc
5
6def leak():
7    class T(type):
8        pass
9    class U(type):
10        __metaclass__ = T
11    U.__class__ = U
12    del U
13    gc.collect(); gc.collect(); gc.collect()
14