anchor.diff:                         end,
   
               ?reply_ok(Headers2, {CacheObj#cache.size, BodyFunc}, Req);
  +
  +        %% MISS: For the case If-Modified-Since matches timestamp in metadata
  +        {ok, #?METADATA{timestamp = IMSSec}, _Resp} ->
  +            ?reply_not_modified([?SERVER_HEADER], Req);
   
           %% MISS: get an object from storage (small-size)
           {ok, #?METADATA{cnumber = 0,
  
positive.code:                                  has_inner_cache = HasInnerCache,
                                   sending_chunked_obj_len = SendChunkLen,
                                   begin_time = BeginTime}) ->
      case leo_gateway_rpc_handler:get(Key) of
          %% For regular case (NOT a chunked object)
          {ok, #?METADATA{cnumber = 0,
                          meta = CMetaBin} = Meta, RespObject} ->
  
negative.code:                                                       custom_header_settings = CustomHeaderSettings,
                                                        sending_chunked_obj_len = SendChunkLen,
                                                        begin_time = BeginTime}) ->
      IMSSec = case cowboy_req:parse_header(?HTTP_HEAD_IF_MODIFIED_SINCE, Req) of
                   {ok, undefined,_} ->
                       0;
                   {ok, IMSDateTime,_} ->
                       calendar:datetime_to_gregorian_seconds(IMSDateTime)
               end,
      Path = CacheObj#cache.file_path,
      HasDiskCache = case Path of
                         [] ->
  