anchor.diff:  
   %% @doc Retrieve redundancies by vnode-id
   %% @private
  +-spec(lookup_fun(list(#ring_group{}), pos_integer(), pos_integer(), pos_integer()) ->
  +             not_found | {ok, #redundancies{}}).
   lookup_fun([],_FirstVNodeId,_LastVNodeId,_AddrId) ->
       not_found;
   lookup_fun(RingGroupList, FirstVNodeId,_LastVNodeId, AddrId) when FirstVNodeId >= AddrId ->
  
positive.code: 
  %% @doc Generate RING for this process
  %% @private
  gen_routing_table(TargetRing,_NumOfReplicas,_NumOfAwarenessL2,_Members) when TargetRing /= ?SYNC_MODE_CUR_RING,
                                                                               TargetRing /= ?SYNC_MODE_PREV_RING ->
      {error, invalid_target_ring};
  
negative.code: 
  %% @doc Retrieve first record
  %% @private
  -spec(first_fun(list(#ring_group{})) ->
               not_found | {ok, #redundancies{}}).
  first_fun([]) ->
      not_found;
  first_fun([#ring_group{vnodeid_nodes_list = AddrId_Nodes_List}|_]) ->
  