Using both `MergeRangeFileReader` and `BufferedStreamReader` simultaneously would waste a lot of memory, so turn off prefetch data in `BufferedStreamReader` when using MergeRangeFileReader.
Using both `MergeRangeFileReader` and `BufferedStreamReader` simultaneously would waste a lot of memory, so turn off prefetch data in `BufferedStreamReader` when using MergeRangeFileReader.