anchor.diff:  
   -include("antidote.hrl").
   
  +%% PVC-Only API
  +-export([start_transaction/0,
  +         read_keys/2,
  +         update_keys/2,
  +         commit_transaction/1]).
  +
   %% API
   -export([
       start_transaction/3,
       start_transaction/2,
  -    commit_transaction/1,
       abort_transaction/1,
       read_objects/2,
       read_objects/3,
  
positive.code:             {ok, []};
          Res -> Res
      end.
  
  abort_transaction(TxId) ->
      cure:abort_transaction(TxId).
  
negative.code:     update_objects/4
  ]).
  
  %% PVC-Only API
  
  start_transaction() ->
      pvc_istart_tx().
  
  commit_transaction(TxId) ->
  