anchor.diff:      {noreply, State}.
   
   %% @private
  +handle_cast(shutdown, State) ->
  +    {stop, normal, State};
  +
   handle_cast(Msg, State) ->
       ?WARN("drain_id=~p channel_id=~p dest=~s err=unexpected_cast data=~p",
             log_info(State, [Msg])),
  
positive.code:                                   port=Port}],
                            []).
  
  %%====================================================================
  %% gen_server callbacks
  %%====================================================================
  
negative.code: 
  %% API
  -export([start_link/4
           ,shutdown/1
          ]).
  
  %% gen_server callbacks
  