anchor.diff:  multicast_register(Name, Pid, Meta) ->
       spawn_link(fun() ->
           lists:foreach(fun(RemoteNode) ->
  -            add_remote_to_local_table(RemoteNode, Name, Pid, Meta)
  +            sync_add(RemoteNode, Name, Pid, Meta)
           end, nodes())
       end).
   
  
positive.code: multicast_unregister(Name) ->
      spawn_link(fun() ->
          lists:foreach(fun(RemoteNode) ->
              remove_remote_from_local_table(RemoteNode, Name)
          end, nodes())
      end).
  
  
negative.code:     %% return
      {noreply, State};
  
  handle_cast({sync_remove, Name}, State) ->
      %% remove
      remove_from_local_table(Name),
      %% return
  