anchor.diff:  to_list(_) -> erlang:nif_error(undef).
   
   
  -%% Shadowed by erl_bif_types: maps:update/3
   -spec update(Key,Value,Map1) -> Map2 when
       Key :: term(),
       Value :: term(),
  
positive.code: remove(_,_) -> erlang:nif_error(undef).
  
  
  %% Shadowed by erl_bif_types: maps:to_list/1
  -spec to_list(Map) -> [{Key,Value}] when
      Map :: map(),
      Key :: term(),
  
negative.code: is_key(_,_) -> erlang:nif_error(undef).
  
  
  -spec keys(Map) -> Keys when
      Map :: map(),
      Keys :: [Key],
  