anchor.diff:      Opts
     ),
     State#{ last_seq => LastSeq1, changes => Changes1}.
  -  
  +
   
   parse_options(Options) ->
     maps:fold(
  
positive.code:     change_fun => ChangeFun,
      changes => queue:new(),
      last_seq => Since},
    
    %% register to the changes
    barrel_event:reg(Db#db.id),
  
  
negative.code:   Since = maps:get(since, Options, 0),
    ChangeCb = maps:get(changes_cb, Options, nil),
    Mode = maps:get(mode, Options, binary),
  
    %% make change callback
    ChangeFun = case {Mode, ChangeCb} of
                  {binary, nil} ->
  