anchor.diff:  wait(Wait) when is_integer(Wait) ->
       gen_server:call(?MODULE, {wait, Wait}). 
   
  -write_test_record(X,FX,OneOverX,Comment) ->
  +write_test_record(X,Y,OneOverX,Label) ->
       Record = #ddTest{ time=os:timestamp()
                       , x=X
  -                    , fX=FX
  +                    , y=Y
                       , oneOverX=OneOverX
  -                    , comment=Comment
  +                    , label=Label
                       },
       imem_meta:write(?ddTestName, Record).
   
  
positive.code: 
  handle_info(next_event, #state{wait=Wait}) ->
      Ran = random:uniform(),         % 0..1
      X = round(50*Ran),              % bad code causing 1/0
      {_,Sec,_} = os:timestamp(),     % {MegaSec,Sec,MicroSec} since epoch
      FX = X * (Sec rem 100 + 1),     % rampy sample distribution
      OneOverX = 5000.0/X,            % spiky sample distribution
      imem_test_writer:write_test_record(X,FX,OneOverX,integer_to_list(fac(X))),
      erlang:send_after(Wait, self(), next_event),
      {noreply, #state{wait=Wait}}.
  
  
negative.code: -record(ddTest,   % test table record definition with erlang types
                    { time      ::ddTimestamp()
                    , x         ::integer()
                    , y         ::integer()
                    , oneOverX  ::float()
                    , label     ::list()
                    }
         ).
  -define(ddTest, [timestamp,integer,integer,float,string]).  % test table DDerl types
  