anchor.diff:      {reply, ok, State};
   
   handle_call(subscribe,_From, State) ->
  -    mnesia:subscribe({table, ?MEMBER_TBL_CUR,  simple}),
  -    mnesia:subscribe({table, ?MEMBER_TBL_PREV, simple}),
       {reply, ok, State};
   
   handle_call(_Handle, _From, State) ->
  
positive.code:     State#state.prev;
  ring_info(_,_) ->
      {error, invalid_table}.
  
  
  
  %% @doc Retrieve vnode-list
  %% @private
  get_vnode_list(?MEMBER_TBL_CUR, undefined,_PrevRing) ->
      [];
  get_vnode_list(?MEMBER_TBL_CUR, [],_PrevRing) ->
      [];
  get_vnode_list(?MEMBER_TBL_CUR, CurRing,_PrevRing) ->
      [#ring_group{vnodeid_nodes_list = VNodeList}|_] = CurRing,
      VNodeList;
  get_vnode_list(?MEMBER_TBL_PREV,_CurRing, undefined) ->
      [];
  get_vnode_list(?MEMBER_TBL_PREV,_CurRing, []) ->
      [];
  get_vnode_list(?MEMBER_TBL_PREV,_CurRing, PrevRing) ->
      [#ring_group{vnodeid_nodes_list = VNodeList}|_] = PrevRing,
      VNodeList.
  
  
  %% @doc Find the node from a part of the ring
  %% @private
  find_node_from_ring([],_Node) ->
      not_found;
  find_node_from_ring([#vnodeid_nodes{nodes = Redundancies}|Rest], Node) ->
      case find_node_from_ring_1(Redundancies, Node) of
          not_found ->
              find_node_from_ring(Rest, Node);
          ok ->
              ok
      end.
  
  %% @private
  find_node_from_ring_1([],_Node) ->
      not_found;
  find_node_from_ring_1([#redundant_node{node = Node}|_], Node) ->
      ok;
  find_node_from_ring_1([_|Rest], Node) ->
      find_node_from_ring_1(Rest, Node).
  
negative.code: %% <p>
  %% gen_server callback - Module:handle_info(Info, State) -> Result.
  %% </p>
  handle_info(_Info, State) ->
      {noreply, State}.
  
  %% @doc This function is called by a gen_server when it is about to
  