anchor.diff:  fetch(Db) ->
       fetch(Db, []).
   
  --spec fetch(Db::db(), Options::changes_options1()) -> {ok,
  +-spec fetch(Db::db(), Options::changes_options()) -> {ok,
           LastSeq::integer(), Rows::list()} | {error,  LastSeq::integer(),
           Error::term()}.
   %% @doc Collect Changes. Could be used to make a blocking call to a
  
positive.code: %%          to send a heartbeat to maintain connection open</li>
  %%      <li><code>{filter, FilterName} | {filter, FilterName, Args::list({key,
  %%          value})</code>: set the filter to use with optional arguments</li>
  %%   </ul></p>
  %%
  %% <p>Resut: <code>{ok, LastSeq::integer(), Rows::list()}</code> or
  %% <code>{error, LastSeq, Error}</code>. LastSeq is the last sequence of changes.</p>
  fetch(Db, Options) ->
      case stream(Db, self(), Options) of
  
negative.code:     parse_changes_options(Rest, Args#changes_args{http_options=Opts1});
  parse_changes_options([heartbeat|Rest], #changes_args{http_options=Opts} = Args) ->
      Opts1 = [{"heartbeat", "true"}|Opts],
      parse_changes_options(Rest, Args#changes_args{http_options=Opts1});
  parse_changes_options([{view, ViewName}|Rest], #changes_args{http_options=Opts} = Args) ->
      Opts1 = [{"view", ViewName}|Opts],
      parse_changes_options(Rest, Args#changes_args{http_options=Opts1});
  parse_changes_options([{filter, FilterName}|Rest], #changes_args{http_options=Opts} = Args) ->
      Opts1 = [{"filter", FilterName}|Opts],
  