@property
    def deleted(self):
        return tuple((p.pkvalue() for p in itervalues(self._deleted)))
Flattening L{Element} instances with the old flatten function results in
dataset/ETHPy150Open lsbardel/python-stdnet/stdnet/odm/session.py/SessionModel.deleted--crossover with--dataset/ETHPy150Open twisted/nevow/nevow/test/test_element.py/FlattenIntegrationTests.test_oldFlattenable