anchor.diff:          [Channel, Payload] -> ok;
           [Channel]          -> Payload = <<>>
       end,
  -    notify_async(State, {notification, Channel, Pid, Payload}),
  -    {noreply, State}.
  +    State2 = notify_async(State, {notification, Channel, Pid, Payload}),
  +    {noreply, State2}.
  
positive.code:     case queue:get(Q) of
          {{cast, From, Ref}, _} ->
              From ! {Ref, Result};
          {{call, From}, _} ->
              gen_server:reply(From, Result)
      end,
  
negative.code:                 rows = [],
                  results = []}.
  
  add_result(State = #state{queue = Q, results = Results}, Notice, Result) ->
      Results2 = case queue:get(Q) of
                     {{incremental, From, Ref}, _} ->
                         From ! {Ref, Notice},
                         Results;
                     _ ->
                         [Result | Results]
                 end,
      State#state{types = [],
                  columns = [],
                  rows = [],
                  results = Results2}.
  
  add_row(State = #state{queue = Q, rows = Rows}, Data) ->
      Rows2 = case queue:get(Q) of
                  {{incremental, From, Ref}, _} ->
                      From ! {Ref, {data, Data}},
                      Rows;
                  _ ->
                      [Data | Rows]
              end,
      State#state{rows = Rows2}.
  
  notify(State = #state{queue = Q}, Notice) ->
      case queue:get(Q) of
          {{incremental, From, Ref}, _} ->
              From ! {Ref, Notice};
          _ ->
              ignore
      end,
      State.
  
  notify_async(State = #state{async = Pid}, Msg) ->
      case is_pid(Pid) of
          true  -> Pid ! {pgsql, self(), Msg};
          false -> false
      end,
      State.
  
  command_tag(#state{queue = Q}) ->
      {_, Req} = queue:get(Q),
  