anchor.diff:  
   %% @doc Declare next key, if undefined.  This function assumes that the
   %%      next key will be declared in the local store.
  +%%
   next_key(undefined, Type, Store) ->
       {ok, NextKey} = declare(druuid:v4(), Type, Store),
       NextKey;
  
positive.code:     NextKey0.
  
  %% @doc Determine if a threshold is met.
  threshold_met(riak_dt_gset, Value, {strict, Threshold}) ->
      is_strict_inflation(riak_dt_gset, Threshold, Value);
  threshold_met(riak_dt_gset, Value, Threshold) ->
  
negative.code:     end.
  
  %% @doc Return the binding status of a given dataflow variable.
  %%
  is_det(Id, Store) ->
      [{_Key, #dv{bound=Bound}}] = ets:lookup(Store, Id),
      {ok, Bound}.
  
  %% @doc Spawn a function.
  %%
  thread(Module, Function, Args, _Store) ->
      Fun = fun() -> erlang:apply(Module, Function, Args) end,
      Pid = spawn(Fun),
  