anchor.diff:  
   %% @doc writes the value of a key
   %% @spec write(key(), value()) -> ok | {fail, term()}
  +-spec write(key(), value()) -> ok | {fail, term()}.
   write(Key, Value) ->
       case util:tc(transaction_api, single_write, [Key, Value]) of
           {_Time, commit} ->
  
positive.code:     end.
  
  %% @doc reads the value of a key
  %% @spec read(key()) -> {failure, term()} | value()
  read(Key) ->
      case util:tc(transaction_api, quorum_read, [Key]) of
          {_Time, {fail, Reason}} ->
  
negative.code: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  
  %% @type key() = term(). Key
  -type(key() :: term()).
  %% @type value() = term(). Value
  -type(value() :: term()).
  
  process_request_list(TLog, ReqList) ->
      erlang:put(instance_id, process_dictionary:find_group(cs_node)),
  