anchor.diff:  fold(Fun,Init,Iterator) when is_function(Fun,3), ?IS_ITERATOR(Iterator) ->
       fold_1(Fun,Init,Iterator);
   fold(Fun,Init,Map) ->
  -    erlang:error(error_type(Map),[Fun,Init,Map]).
  +    erlang:error(error_type_iter(Map),[Fun,Init,Map]).
   
   fold_1(Fun, Acc, Iter) ->
       case next(Iter) of
  
positive.code: map(Fun,Iterator) when is_function(Fun, 2), ?IS_ITERATOR(Iterator) ->
      maps:from_list(map_1(Fun, Iterator));
  map(Fun,Map) ->
      erlang:error(error_type(Map),[Fun,Map]).
  
  map_1(Fun, Iter) ->
      case next(Iter) of
  
negative.code:     erlang:error(error_type(M),[Ks,M]).
  
  
  error_type(M) when is_map(M) -> badarg;
  error_type(V) -> {badmap, V}.
  
  error_type_iter(M) when is_map(M); ?IS_ITERATOR(M) -> badarg;
  error_type_iter(V) -> {badmap, V}.
  