rollback transactional kvs:add, anyway it's slow and unused

src/kvs.erl

@@ -138,7 +138,7 @@ link(Record,#kvs{mod=_Store}=Driver) ->
               {ok, Exists} -> ensure_link(Exists, Driver);
         {error, not_found} -> {error, not_found} end.
 
-add(Record, #kvs{mod=store_mnesia}=Driver) when is_tuple(Record) -> store_mnesia:add(Record);
+%add(Record, #kvs{mod=store_mnesia}=Driver) when is_tuple(Record) -> store_mnesia:add(Record);
 add(Record, #kvs{mod=Store}=Driver) when is_tuple(Record) -> append(Record,Driver).
 
 append(Record, #kvs{mod=_Store}=Driver) when is_tuple(Record) ->