anchor.diff:  %% extract keydata from the input
   erlang_keydata({_OkError, _Input, KeyData}) -> KeyData.
   
  +%% @doc Evaluate Javascript map functions ... if the input is ok.
   map_js(_JS, _Arg, {{error, notfound}, {Bucket, Key}, KeyData}) ->
       {ok, [{not_found,
              {Bucket, Key},
  
positive.code: 
  -define(DEFAULT_JS_RESERVE_ATTEMPTS, 10).
  
  %% @doc Init just stashes everything for later.
  -spec init(riak_pipe_vnode:partition(), riak_pipe_fitting:details()) ->
           {ok, state()}.
  init(Partition, #fitting_details{arg={Phase, Arg}}=FittingDetails) ->
      case init_phase(Phase) of
          {ok, LocalPhase} ->
  
negative.code:         
  %% @doc Evaluate the map function.
  -spec map(riak_kv_mrc_pipe:map_query_fun(), term(), term())
           -> {ok, [term()]}
            | {forward_preflist, Reason :: term()}
            | {error, Reason :: term()}.
  map({modfun, Module, Function}, Arg, Input0) ->
      Input = erlang_input(Input0),
      KeyData = erlang_keydata(Input0),
  