anchor.diff:  
   %% @doc Retrieve redundancies from the ring-table.
   %%
  +-spec(get_redundancies_by_addr_id(integer()) ->
  +             {ok, #redundancies{}} | {error, any()}).
   get_redundancies_by_addr_id(AddrId) ->
       get_redundancies_by_addr_id(default, AddrId).
   
   -spec(get_redundancies_by_addr_id(method(), integer()) ->
  -             {ok, list(), integer(), integer(), list()} | {error, any()}).
  +             {ok, #redundancies{}} | {error, any()}).
   get_redundancies_by_addr_id(Method, AddrId) ->
       ServerRef = get_server_id(AddrId),
       get_redundancies_by_addr_id(ServerRef, Method, AddrId).
   
   -spec(get_redundancies_by_addr_id(atom(), method(), integer()) ->
  -             {ok, list(), integer(), integer(), list()} | {error, any()}).
  +             {ok, #redundancies{}} | {error, any()}).
   get_redundancies_by_addr_id(ServerRef, Method, AddrId) ->
       case leo_misc:get_env(?APP, ?PROP_OPTIONS) of
           {ok, Options} ->
  
positive.code:     end.
  
  %% @private
  get_redundancies_by_addr_id_1(ServerRef, TblInfo, AddrId, Options) ->
      N = leo_misc:get_value(?PROP_N, Options),
      R = leo_misc:get_value(?PROP_R, Options),
  
negative.code: %% @doc Retrieve redundancies from the ring-table.
  %%
  -spec(get_redundancies_by_key(string()) ->
               {ok, #redundancies{}} | {error, any()}).
  get_redundancies_by_key(Key) ->
      get_redundancies_by_key(default, Key).
  
  -spec(get_redundancies_by_key(method(), string()) ->
               {ok, #redundancies{}} | {error, any()}).
  get_redundancies_by_key(Method, Key) ->
      case leo_misc:get_env(?APP, ?PROP_OPTIONS) of
          {ok, Options} ->
  