anchor.diff:          field07 => binary,
           field08 => host,
           field09 => host6,
  -        field10 => {'fun', fun parse_fun/3},
  +        field10 => fun parse_fun/3,
           field11 => [{enum, [a]}, binary],
           fieldXX => invalid
       },
  
positive.code:     {integer, [integer()]} | {record, atom()} |
      string | binary | lower | upper |
      ip | host | host6 | {function, pos_integer()} |
      {'fun', 
          fun((atom(), term(), [{atom(), term()}]) -> 
              ok | {ok, term()} | {opts, [{atom(), term()}]} | error)
      } |
      unquote | path.
  
  -type parse_spec() :: #{ atom() => parse_opt()}.
  
  
negative.code: 
      {error, {invalid_atom, "12345"}} = parse_config([{field01, "12345"}], Spec),
      
      {ok,[{field01, fieldXX}, {field02, false}],[{"unknown", a}]} = 
          parse_config(
              [{field01, "fieldXX"}, {field02, <<"false">>}, {"unknown", a}],
              Spec),
  