non-iterator-returned:79:4:80:17:FirstBadIterator.__iter__:__iter__ returns non-iterator:UNDEFINED
non-iterator-returned:86:4:87:19:SecondBadIterator.__iter__:__iter__ returns non-iterator:UNDEFINED
non-iterator-returned:93:4:94:34:ThirdBadIterator.__iter__:__iter__ returns non-iterator:UNDEFINED
non-iterator-returned:100:4:101:31:FourthBadIterator.__iter__:__iter__ returns non-iterator:UNDEFINED
