anchor.diff:  find(_,_) -> erlang:nif_error(undef).
   
   
  -%% Shadowed by erl_bif_types: maps:from_list/1
  --spec from_list([{Key,Value}]) -> Map when
  +-spec from_list(List) -> Map when
  +    List :: [{Key,Value}],
       Key :: term(),
       Value :: term(),
       Map :: map().
  
positive.code: 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(),
  
negative.code: remove(_,_) -> erlang:nif_error(undef).
  
  
  -spec to_list(Map) -> [{Key,Value}] when
      Map :: map(),
      Key :: term(),
  