def popitem(self):
        try:
            k, v = self.iteritems().next()
        except __HOLE__:
            raise KeyError('container is empty')
        del self[k]
        return (k, v)
dataset/ETHPy150Open OpenMDAO/OpenMDAO-Framework/openmdao.lib/src/openmdao/lib/casehandlers/pymongo_bson/son.py/SON.popitem