def get_docs_to_commit(self):
        try:
            spec = {'synced': False}
            fields = {'_id': 0}
            cur = self.db.docs.find(spec, fields)
        except Exception as e:
            raise DatabaseException(e)
        return list(cur)
def _raise_or_warn(self, warn_only, msg):
        if warn_only:
            self._warnings.append(msg)
        else:
            raise TransactionError(msg)