anchor.diff:      {ok, #state{address = Address, port = Port, queue = queue:new()}}.
   
   %% @private
  -handle_call({req, Msg, Timeout}, From, State) when State#state.pending =/= undefined;
  +handle_call({req, Msg, Timeout}, From, State) when State#state.active =/= undefined;
                                                      State#state.sock =:= undefined ->
       {noreply, queue_request(new_request(Msg, From, Timeout), State)};
  -handle_call({req, Msg, Timeout, Ctx}, From, State) when State#state.pending =/= undefined;
  +handle_call({req, Msg, Timeout, Ctx}, From, State) when State#state.active =/= undefined;
                                                           State#state.sock =:= undefined ->
       {noreply, queue_request(new_request(Msg, From, Timeout, Ctx), State)};
   handle_call({req, Msg, Timeout}, From, State) ->
  
positive.code: -record(state, {address,    % address to connect to
                  port,       % port to connect to
                  sock,       % gen_tcp socket
                  pending,    % active request
                  queue,      % queue of pending requests
                  connects=0, % number of successful connects
                  failed=[],  % breakdown of failed connects
  
negative.code: %% ====================================================================
  
  maybe_reply({reply, Reply, State}) ->
      Request = State#state.active,
      NewRequest = send_caller(Reply, Request),
      State#state{active = NewRequest};
  maybe_reply({noreply, State}) ->
      State.
  
  