anchor.diff:      {'EXIT', {badarg,_}} = (catch maps:from_list(id(42))),
       ok.
   
  +%% Maps module, not BIFs
  +t_maps_fold(_Config) ->
  +
  +    Vs = lists:seq(1,100),
  +    Rs = lists:reverse(Vs),
  +    M  = maps:from_list([{{k,I},{v,I}}||I<-Vs]),
  +
  +    %% foldl
  +    5050 = maps:foldl(fun({k,_},{v,V},A) -> V + A end, 0, M),
  +    Rs = maps:foldl(fun({k,_},{v,V},A) -> [V|A] end, [], M),
  +
  +    %% foldr
  +    5050 = maps:foldr(fun({k,_},{v,V},A) -> V + A end, 0, M),
  +    Vs = maps:foldr(fun({k,_},{v,V},A) -> [V|A] end, [], M),
  +
  +    ok.
  +
  +t_maps_map(_Config) ->
  +    Vs = lists:seq(1,100),
  +    M1 = maps:from_list([{I,I}||I<-Vs]),
  +    M2 = maps:from_list([{I,{token,I}}||I<-Vs]),
  +
  +    M2 = maps:map(fun(_K,V) -> {token,V} end, M1),
  +    ok.
  +
  +t_maps_size(_Config) ->
  +    Vs = lists:seq(1,100),
  +    lists:foldl(fun(I,M) ->
  +		M1 = maps:put(I,I,M),
  +		I  = maps:size(M1),
  +		M1
  +	end, #{}, Vs),
  +    ok.
  +
  +
  +t_maps_without(_Config) ->
  +    Ki = [11,22,33,44,55,66,77,88,99],
  +    M0 = maps:from_list([{{k,I},{v,I}}||I<-lists:seq(1,100)]),
  +    M1 = maps:from_list([{{k,I},{v,I}}||I<-lists:seq(1,100) -- Ki]),
  +    M1 = maps:without([{k,I}||I <- Ki],M0),
  +    ok.
  +
  +
   %% MISC
   t_pdict(_Config) ->
   
  
positive.code: 	t_erlang_hash/1,
  	t_map_encode_decode/1,
  
  	%% misc
  	t_pdict/1,
  	t_ets/1,
  
negative.code: 
  	%% erlang
  	t_erlang_hash, t_map_encode_decode,
  	t_map_size,
  
  	%% maps module
  	t_maps_fold, t_maps_map,
  	t_maps_size, t_maps_without,
  
  
          %% Other functions
  	t_pdict,
  