anchor.diff:      DataDiff = lists:subtract(Data, UniqueData),
       case FailOnError of
           true ->
  -            ?equals_w_note(DataDiff, [], "duplicate elements detected");
  +            ?equals_w_note(DataDiff, [], "duplicate elements detected"),
  +            true;
           _ when DataDiff =:= [] ->
               true;
           _ ->
  
positive.code:         check_ring_data_lock_free(Data, FailOnError) andalso
          check_ring_data_repl_exist(Data, FailOnError).
  
  -spec check_ring_data_unique(Data::[db_entry:entry()], FailOnError::boolean()) -> ok.
  check_ring_data_unique(Data, FailOnError) ->
      UniqueData = lists:usort(fun(A, B) ->
                                       db_entry:get_key(A) =< db_entry:get_key(B)
  
negative.code:             false
      end.
  
  -spec check_ring_data_lock_free(Data::[db_entry:entry()], FailOnError::boolean()) -> boolean().
  check_ring_data_lock_free(Data, FailOnError) ->
      Locked = [E || E <- Data, db_entry:is_locked(E)],
      case FailOnError of
          true ->
              ?equals_w_note(Locked, [], "ring is not lock-free"),
              true;
          _ when Locked =:= [] ->
              true;
          _ ->
  