def delete(self, doc):
        if doc.id is None:
            raise DatabaseException('Document does not have id')
        if doc.sid is None:
            try:
                rs = self.db.docs.remove({'id': doc.id}, safe=True)
                assert rs['n'] == 1
            except Exception as e:
                raise DatabaseException(e)
            return None
        doc.data = None
        return self.update(doc)
def setUp(self):
        entry_Li = ComputedEntry("Li", -1.90753119)

        with open(os.path.join(PymatgenTest.TEST_FILES_DIR, "LiTiO2_batt.json")) as f:
            entries_LTO = json.load(f, cls=MontyDecoder)
            self.ie_LTO = InsertionElectrode.from_entries(entries_LTO, entry_Li)

        with open(os.path.join(PymatgenTest.TEST_FILES_DIR, "FeF3_batt.json")) as fid:
            entries = json.load(fid, cls=MontyDecoder)
            self.ce_FF = ConversionElectrode.from_composition_and_entries(Composition("FeF3"), entries)