non-iterator-returned:63:FirstBadIterator.__iter__:__iter__ returns non-iterator
non-iterator-returned:69:SecondBadIterator.__iter__:__iter__ returns non-iterator
non-iterator-returned:75:ThirdBadIterator.__iter__:__iter__ returns non-iterator
non-iterator-returned:81:FourthBadIterator.__iter__:__iter__ returns non-iterator
non-iterator-returned:87:FifthBadIterator.__iter__:__iter__ returns non-iterator