anchor.diff:  
   update_doc(_Config) ->
     Doc = #{ <<"id">> => <<"a">>, <<"v">> => 1},
  -  {ok, <<"a">>, RevId} = barrel_local:put(<<"testdb">>, Doc, []),
  +  {ok, <<"a">>, RevId} = barrel_local:post(<<"testdb">>, Doc, []),
     {ok, Doc, _Meta2} = barrel_local:get(<<"testdb">>, <<"a">>, []),
     Doc2 = Doc#{ v => 2},
     {ok, <<"a">>, RevId2} = barrel_local:put(<<"testdb">>, Doc2, [{rev, RevId}]),
  
positive.code: 
  async_update(_Config) ->
    Doc = #{ <<"id">> => <<"a">>, <<"v">> => 1},
    ok= barrel_local:put(<<"testdb">>, Doc, [{async, true}]),
    timer:sleep(100),
    {ok, #{ <<"id">> := <<"a">>, <<"v">> := 1}, _} = barrel_local:get(<<"testdb">>, <<"a">>, []).
  
  resource_id(_Config) ->
    Doc = #{ <<"id">> => <<"a">>, <<"v">> => 1},
    {ok, <<"a">>, RevId} = barrel_local:put(<<"testdb">>, Doc, []),
    {ok, _, #{ <<"rev">> := RevId, <<"rid">> := Rid}} = barrel_local:get(<<"testdb">>, <<"a">>, [{meta, true}]),
    1 = barrel_db:decode_rid(Rid),
    {ok, <<"a">>, RevId2} = barrel_local:put(<<"testdb">>, Doc, [{rev, RevId}]),
    {ok, _, #{ <<"rev">> := RevId2, <<"rid">> := Rid}} = barrel_local:get(<<"testdb">>, <<"a">>, [{meta, true}]),
    Doc2 = #{ <<"id">> => <<"b">>, <<"v">> => 1},
    {ok, <<"b">>, _} = barrel_local:put(<<"testdb">>, Doc2, []),
    {ok, _, #{ <<"rid">> := Rid2}} = barrel_local:get(<<"testdb">>, <<"b">>, [{meta, true}]),
    2 = barrel_db:decode_rid(Rid2).
  
  
negative.code:   {ok, Doc2, _Meta4} = barrel_local:get(<<"testdb">>, <<"a">>, []),
    {ok, <<"a">>, _RevId2} = barrel_local:delete(<<"testdb">>, <<"a">>, [{rev, RevId2}]),
    {error, not_found} = barrel_local:get(<<"testdb">>, <<"a">>, []),
    {ok, <<"a">>, _RevId3} = barrel_local:post(<<"testdb">>, Doc, []).
  
  
  revision_conflict(_Config) ->
    Doc = #{ <<"id">> => <<"a">>, <<"v">> => 1},
    {ok, _, RevId} = barrel_local:post(<<"testdb">>, Doc, []),
    {ok, Doc1, _} = barrel_local:get(<<"testdb">>, <<"a">>, []),
    Doc2 = Doc1#{ <<"v">> => 2 },
    {ok, <<"a">>, _RevId2} = barrel_local:put(<<"testdb">>, Doc2, [{rev, RevId}]),
  