anchor.diff:  
   %% gen_server callbacks
   -export([init/1,on/2,
  -    
  -	 register_process/3, 
  -	 lookup_process/2,
  -	 lookup_process/1,
  -	 find_cs_node/0, 
  -	 find_all_cs_nodes/0, 
  -	 find_all_processes/1, 
  -	 find_group/1,
  +         register_process/3,
  +         lookup_process/2,
  +         lookup_process/1,
  +         find_cs_node/0,
  +         find_all_cs_nodes/0,
  +         find_all_processes/1,
  +         find_group/1,
            find_all_groups/1,
   
  -	 get_groups/0,
  -	 get_processes_in_group/1, 
  -	 %get_info/2,
  -
  -	 %for fprof
  -	 get_all_pids/0]).
  +         get_groups/0,
  +         get_processes_in_group/1,
  +         %get_info/2,
  +
  +         %for fprof
  +         get_all_pids/0]).
   
   %% for unit testing
   -export([start_link_for_unittest/0]).
  
positive.code: %% @doc register a process with InstanceId and Name
  %% @spec register_process(term(), term(), pid()) -> ok
  register_process(InstanceId, Name, Pid) ->
      
      erlang:put(instance_id, InstanceId),
      erlang:put(instance_name, Name),
      cs_send:send_local(get_pid() , {register_process, InstanceId, Name, Pid}),
  
negative.code: 
  %@private
  
  -spec(on/2 :: (any(), null) -> null).
  on({register_process, InstanceId, Name, Pid}, State) ->
      case ets:insert_new(?MODULE, {{InstanceId, Name}, Pid}) of
          true ->
              link(Pid);
          false ->
              OldPid = ets:lookup_element(?MODULE, {InstanceId, Name}, 2),
              unlink(OldPid),
              link(Pid),
              ets:insert_new(?MODULE, {{InstanceId, Name}, Pid})
      end,
      cs_send:send_local(Pid , {ok}),
      State;
  on({drop_state}, State) ->
      % only for unit tests
      Links = ets:match(?MODULE, {'_', '$1'}),
      [unlink(Pid) || [Pid] <- Links],
      ets:delete_all_objects(?MODULE),
      State;
  on({'EXIT', FromPid, _Reason}, State) ->
      Processes = ets:match(?MODULE, {'$1', FromPid}),
      [ets:delete(?MODULE, {InstanceId, Name}) || [{InstanceId, Name}] <- Processes],
      State;
  on(_, _State) ->
      unknown_event.
  
  