anchor.diff:  	name :: string(),
   	chatters :: [pid()],
   	controllers :: [pid()],
  -	mode = user :: 'user' | 'system' | 'plugin'
  +	mode = user :: 'user' | 'system' | 'plugin',
   	mode_meta
   }).
   
   -record(system_opts, {
   	display = shown :: 'shown' | 'hidden',
  -	leavable = 'leavers' | 'no_leavers',
  -	kicking = 'kick' | 'no_kick',
  -	muting = 'mute' | 'no_mute'
  +	leavable = leavers :: 'leavers' | 'no_leavers',
  +	kicking = kick :: 'kick' | 'no_kick',
  +	muting = mute :: 'mute' | 'no_mute'
   }).
   
   %% ==================================================================
  
positive.code: 
  build_system_opts([leavers | Tail], Rec) ->
  	Rec0 = Rec#system_opts{leavable = leavers},
  	build_sytem_opts(Tail, Rec0);
  
  build_system_opts([no_leavers | Tail], Rec) ->
  	Rec0 = Rec#system_opts{leavable = no_leavers},
  
negative.code: 	State = #state{name = Name, mode = Mode},
  	case Mode of
  		user when is_record(ModeMeta, client_info) ->
  			#client_info{connection = Conn} = ModeMeta,
  			Chatters = [ModeMeta],
  			Controller = [Conn],
  			State0 = State#state{chatters = Chatters, controllers = Controller},
  			{ok, State0};
  		plugin when is_record(ModeMeta, client_info) ->
  			#client_info{connection = Conn} = ModeMeta,
  			Chatters = [Conn],
  			State0 = State#state{chatters = Chatters},
  			{ok, State0};
  