anchor.diff:              gen_server:call(Pid, {quarantine_channel, ChannelId})
       end.
   
  +unquarantine_channel(ChannelId) when is_integer(ChannelId) ->
  +    gen_server:call(?MODULE, {unquarantine_channel, ChannelId}).
  +
   %%====================================================================
   %% gen_server callbacks
   %%====================================================================
  
positive.code: -export([start_link/0
           ,channel/1
           ,quarantine_channel/1
          ]).
  
  %% gen_server callbacks
  
negative.code:     Result = ets:insert(?TABLE, {{channel, ChannelId},
                                   os:timestamp()}),
      {reply, Result, State};
  handle_call({unquarantine_channel, ChannelId}, _From, State)
    when is_integer(ChannelId) ->
      Result = ets:delete(?TABLE, {channel, ChannelId}),
      {reply, Result, State};
  handle_call(Call, _From, State) ->
      ?WARN("Unexpected call ~p.", [Call]),
  