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:

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