anchor.diff:  
   -spec delete_links4(model_behaviour:model_config(), datastore:ext_key(), [datastore:normalized_link_spec()] | all, InternalCtx :: term()) ->
       ok | datastore:generic_error().
  -delete_links4(#model_config{bucket = Bucket, name = ModelName} = ModelConfig, Key, [], Ctx) ->
  -    case save(ModelConfig, #document{key = links_doc_key(Bucket, Key), value = #links{key = Key, model = ModelName, link_map = Ctx}}) of
  +delete_links4(#model_config{bucket = _Bucket, name = ModelName} = ModelConfig, Key, [], Ctx) ->
  +    case save(ModelConfig, #document{key = links_doc_key(Key), value = #links{key = Key, model = ModelName, link_map = Ctx}}) of
           {ok, _} -> ok;
           {error, Reason} ->
               {error, Reason}
  
positive.code: -export([init_bucket/3, healthcheck/1, init_driver/1]).
  -export([save/2, create/2, update/3, create_or_update/3, exists/2, get/2, list/3, delete/3]).
  -export([add_links/3, delete_links/3, fetch_link/3, foreach_link/4]).
  -export([links_key_to_doc_key/1]).
  
  -export([start_gateway/4, force_save/2, db_run/4]).
  
  
negative.code: -spec foreach_link(model_behaviour:model_config(), Key :: datastore:ext_key(),
      fun((datastore:link_name(), datastore:link_target(), Acc :: term()) -> Acc :: term()), AccIn :: term()) ->
      {ok, Acc :: term()} | datastore:link_error().
  foreach_link(#model_config{bucket = _Bucket} = ModelConfig, Key, Fun, AccIn) ->
      case get(ModelConfig, links_doc_key(Key)) of
          {ok, #document{value = #links{link_map = LinkMap}}} ->
              {ok, maps:fold(Fun, AccIn, LinkMap)};
          {error, {not_found, _}} ->
  