def update_txn_with_extra_data(self, txn):
        """
        All the data of the transaction might not be stored in ledger so the
        extra data that is omitted from ledger needs to be fetched from the
        appropriate data store
        :param txn:
        :return:
        """
        # For RAW and ENC attributes, only hash is stored in the ledger.
        if get_type(txn) == ATTRIB:
            txn_data = get_payload_data(txn)
            # The key needs to be present and not None
            key = RAW if (RAW in txn_data and txn_data[RAW] is not None) else \
                ENC if (ENC in txn_data and txn_data[ENC] is not None) else None
            if key:
                txn_data[key] = self.attributeStore.get(txn_data[key])
        return txn
All the data of the transaction might not be stored in ledger so the
        extra data that is omitted from ledger needs to be fetched from the
        appropriate data store
        :param txn:
        :return: