docs: def transform_txn_for_ledger(txn):
          """
          Some transactions need to be transformed before they can be stored in the
          ledger, eg. storing certain payload in another data store and only its
          hash in the ledger
          """
          if get_type(txn) == ATTRIB:
              txn = DomainReqHandler.transform_attrib_for_ledger(txn)
          return txn