anchor.diff:  %%%============================================================================
   %%% Internal functionality
   %%%============================================================================
  -do_download(#state{port = undefined, queue =  Queue} = State) ->
  +do_download(#state{queue = Queue} = State) ->
      case queue:out(Queue) of
         {{value, Url}, Queue2} ->
              vffov_common:verbose(info, "Downloading video from url ~s", [Url]),
  
positive.code:        _ ->
             {stop, normal, State#state{queue = [], current_url = []}}
     end;
  do_download(#state{port = Port} = State) ->
      vffov_common:close_downloader_port(Port),
      do_download(State#state{port = undefined}).
  
negative.code: %% API
  -export([
           start_link/2,
           stop/0,
           get_url/0,
           get_queue/0
          ]).
  
  %% gen_server callbacks
  