def _drop(self):
        stmts = []
        for fdw in self:
            if hasattr(self[fdw], 'dropped'):
                stmts.append(self[fdw].drop())
        return stmts
Actually drop the wrappers
dataset/ETHPy150Open perseas/Pyrseas/pyrseas/dbobject/foreign.py/ForeignDataWrapperDict._drop