anchor.diff:  
   %% @doc Harness for managing the fold operation.
   %% TODO: needs to perform a blocking threshold read for new values.
  -foldl_harness(Node, Partition, Variables, Id, Function, AccId) ->
  +foldl_harness(Node, Partition, Variables, Id, Function, AccId, Previous) ->
       lager:info("Fold executing!"),
  +    {ok, Type, Value, _} = derflow_ets:read(Id, {strict, Previous}, Variables),
  +    lager:info("Threshold was met!"),
       [{_Key, #dv{type=Type, value=Value}}] = ets:lookup(Variables, Id),
   
       %% Generate operations for given data type.
       {ok, Operations} = derflow_ets:generate_operations(Type, Value),
  +    lager:info("Operations generated: ~p", [Operations]),
   
       %% Build new data structure.
       AccValue = lists:foldl(
  
positive.code:             %% We're remote, go through all of the routing logic.
              bind(AccId, AccValue)
      end,
      foldl_harness(Node, Partition, Variables, Id, Function, AccId).
  
negative.code:          handle_coverage/4,
           handle_exit/3]).
  
  -export([foldl_harness/7]).
  
  -ignore_xref([start_vnode/1]).
  
  