anchor.diff:                                                        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
                          [] ->
  
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:                    end,
  
      case leo_gateway_rpc_handler:get(Key, CacheObj#cache.etag) of
          %% HIT: For the case If-Modified-Since matches mtime in cache
          {ok, match} when CacheObj#cache.mtime == IMSSec ->
              ?reply_not_modified([?SERVER_HEADER], Req);
  
          %% HIT: get an object from disc-cache
          {ok, match} when Path /= []
                           andalso HasDiskCache ->
  