anchor.diff:  %% <pre>even() ->
   %%    domain(even,
   %%      fun(Self,Size) ->
  -%%            Value = (random:uniform(Size) * 2) div 2,
  +%%            Value = (rand:uniform(Size) * 2) div 2,
   %%            {Self, Value}
   %%      end,
   %%      fun(Self,Value) when Value>0 ->
  
positive.code:            SampleSize) ->
  
      OutLen = if EmptyOK =:= false ->
                       random:uniform(SampleSize);
                  EmptyOK =:= true ->
                       random:uniform(SampleSize)-1
               end,
  
      %%
  
negative.code: %%
  -spec map() -> domrec(map()).
  map() -> 
      #?DOM{kind = #map{},
            pick = fun map_pick/2,
           shrink = fun map_shrink/2}.
  
  map_pick(Dom = #?DOM{kind=#map{}}, SampleSize) ->
      NewMap = foldn(
        fun(A) ->
            {_Dom1, KeyVal} = pick(arbitrary_term(0), 2), % TODO: why does 1 not work for samplesize
  