anchor.diff:          parse_config([{field01, a}, {field14, 1}, {field15, b}], Spec, #{return=>map}),
   
       {error, {syntax_error, <<"field14">>}} = parse_config(#{field01=>a, field14=>a}, Spec),
  +
  +    {error, {syntax_error, <<"field16">>}} = parse_config([{field16, kkk383838}], Spec),
  +    {ok, [{field16, string}], []} = parse_config([{field16, string}], Spec),
  +
       ok.
   
   
  
positive.code:         return => map|list,         % Default is list
          path => binary(),           % Returned in errors
          defaults => map() | list(),
          mandatory => [atom()]
      }.
  
  
  
negative.code:     Mandatory = maps:get(mandatory, Opts, []),
      case check_mandatory(Mandatory, OK) of
          ok ->
              case NoOK /= [] andalso maps:find(warning_unknown, Opts) of
                  {ok, true} ->
                      lager:warning("Unknown keys in config: ~p", 
                                    [maps:from_list(NoOK)]);
                  _ -> ok
              end,
              case Opts of
                  #{return:=map} ->
                      {ok, maps:from_list(OK2), maps:from_list(NoOK)};
  