anchor.diff:      [ [H|X] || X <- PT ] ++ PT.
   
   %% @private
  -encode_and_write_json_dnf(FailedOmissions) ->
  -    %% Generate disjunctive normal form representation of failures that will invalidate the entire trace.
  -    FinalDNF = lists:foldl(fun(Omissions, DNF) ->
  -        CNF = lists:foldl(fun({Type, Message}, CNF1) ->
  -            {TracingNode, InterpositionType, OriginNode, MessagePayload} = Message,
  -
  -            NewObject = [
  -                {type, Type},
  -                {tracing_node, TracingNode},
  -                {origin_node, OriginNode},
  -                {interposition_type, InterpositionType},
  -                {message_payload, format_message_payload_for_json(MessagePayload)}
  -            ],
  -
  -            %% Add conjunct for the omission.
  -            CNF1 ++ [NewObject]
  -        end, [], Omissions),
  -
  -        DNF ++ [CNF]
  -    end, [], FailedOmissions),
  -
  -    %% Write out JSON file with the DNF.
  -    EncodedJsonTrace = jsx:encode(FinalDNF),
  -    JsonOutputFile = dnf_file(),
  -    io:format("Writing JSON DNF.~n", []),
  -    {ok, Io} = file:open(JsonOutputFile, [write, {encoding, utf8}]),
  -    io:format(Io, "~s", [jsx:prettify(EncodedJsonTrace)]),
  -    file:close(Io),
  -
  -    ok.
  -
  -%% @private
  -format_message_payload_for_json(MessagePayload) ->
  -    list_to_binary(lists:flatten(io_lib:format("~w", [MessagePayload]))).
  -
  -%% @private
   implementation_module() ->
       case os:getenv("IMPLEMENTATION_MODULE") of 
           false ->
  
positive.code:     io:format("Test took: ~p~n", [timer:now_diff(EndTime, StartTime)]),
  
      ok.
  
  %% @private
  dnf_file() ->
      "/tmp/partisan-dnf.json".
  
  %% @doc Generate the powerset of messages.
  powerset([]) -> 
  
negative.code:     io:format("Out of ~p traces found ~p that supported the execution where ~p didn't.~n", 
                [length(TracesToIterate), length(PassedOmissions), length(FailedOmissions)]),
  
      %% Test finished time.
      EndTime = os:timestamp(),
  
  