anchor.diff:  
   
   apply_user_fun(CAcc, Doc) ->
  +    FinalDoc = mango_fields:extract(Doc, CAcc#cacc.fields),
       #cacc{
           user_fun = UserFun,
           user_acc = UserAcc
       } = CAcc,
  -    case UserFun({row, Doc}, UserAcc) of
  +    case UserFun({row, FinalDoc}, UserAcc) of
           {ok, NewUserAcc} ->
               CAcc#cacc{user_acc = NewUserAcc};
           {stop, NewUserAcc} ->
  
positive.code:     Limit = if Limit0 < 50 -> Limit0; true -> 50 end,
      Skip = couch_util:get_value(skip, Opts, 0),
      Fields = couch_util:get_value(fields, Opts, all_fields),
  
      {ok, #cursor{
          db = Db,
          index = Index,
  
negative.code:     limit,
      skip,
      user_fun,
      user_acc,
      fields
  }).
  
  
  