anchor.diff:  	    {<<"hi">>,v6}, {{hi,3},v10},{"hi",v11}, {hi,v9}, {3,v8}]),
   
       %% error cases
  +    {'EXIT', {badarg,_}} = (catch maps:from_list(id([{a,b},b]))),
  +    {'EXIT', {badarg,_}} = (catch maps:from_list(id([{a,b},{b,b,3}]))),
  +    {'EXIT', {badarg,_}} = (catch maps:from_list(id([{a,b},<<>>]))),
  +    {'EXIT', {badarg,_}} = (catch maps:from_list(id([{a,b}|{b,a}]))),
       {'EXIT', {badarg,_}} = (catch maps:from_list(id(a))),
       {'EXIT', {badarg,_}} = (catch maps:from_list(id(42))),
       ok.
  
positive.code:     false = maps:is_key("h", M1),
      false = maps:is_key("hello", M1),
      false = maps:is_key(atom, M1),
  
      false = maps:is_key("hi", maps:remove("hi", M1)),
      true  = maps:is_key("hi", M1),
      true  = maps:is_key(1, maps:put(1, "number", M1)),
      false = maps:is_key(1.0, maps:put(1, "number", M1)),
      ok.
  
  t_bif_map_keys(Config) when is_list(Config) ->
  
negative.code: 
      [4,18446744073709551629,int,"hi",<<"key">>] = maps:keys(M5),
      [number,wat,3,"hello",<<"value">>]          = maps:values(M5),
  
      M6 = #{ <<"key">> := <<"other value">> } = maps:put(<<"key">>, <<"other value">>, M5),
  
      [4,18446744073709551629,int,"hi",<<"key">>] = maps:keys(M6),
      [number,wat,3,"hello",<<"other value">>]    = maps:values(M6),
  
      %% error case
      {'EXIT',{badarg,[{maps,put,_,_}|_]}} = (catch maps:put(1,a,1 bsl 65 + 3)),
  