ops     fileOps
			wantCnt int64
			wantErr error
		}
		testRemaining struct { // logicalRemaining() == wantLCnt, physicalRemaining() == wantPCnt
			wantLCnt int64
			wantPCnt int64
		}
		testFnc any // testRead | testWriteTo | testRemaining
	)

	type (
		makeReg struct {
			str  string
			size int64
		}
		makeSparse struct {
			makeReg makeReg

	r      *io.PipeReader
	wg     *sync.WaitGroup
	buffer map[int64][]byte
	err    error

	nextOffset int64
	m          sync.Mutex
}

func (w *writerAt) WriteAt(b []byte, offset int64) (n int, err error) {
	w.m.Lock()
	defer w.m.Unlock()

	if w.nextOffset == offset {
		n, err = w.w.Write(b)
		w.nextOffset += int64(n)
	} else {
		if offset > w.nextOffset+ftpMaxWriteOffset {

		{bucketNames[0], objectNames[0], uploadIDs[0], 4, "mnop", "e132e96a5ddad6da8b07bba6f6131fef", int64(len("abcd"))},
		// Part with size larger than 5Mb.
		{bucketNames[0], objectNames[0], uploadIDs[0], 5, string(validPart), validPartMD5, int64(len(validPart))},
		{bucketNames[0], objectNames[0], uploadIDs[0], 6, string(validPart), validPartMD5, int64(len(validPart))},

		err = xl.Load(data)
		if err != nil {
			t.Fatal(err)
		}
		for _, v := range xl.versions {
			// Signature should match
			if binary.BigEndian.Uint32(v.header.Signature[:]) != 0x8e5a6406 {
				t.Log(v.header.String())
				t.Fatalf("invalid signature 0x%x", binary.BigEndian.Uint32(v.header.Signature[:]))
			}
		}
	})
}

func Test_xlMetaV2Shallow_LoadTimeStamp(t *testing.T) {
	// v0 Saved with

}

// Test the predicted part size from the part index
func TestGetPartSizeFromIdx(t *testing.T) {
	// Create test cases
	testCases := []struct {
		totalSize    int64
		partSize     int64
		partIndex    int
		expectedSize int64
	}{
		// Total size is zero
		{0, 10, 1, 0},
		// part size 2MiB, total size 4MiB
		{4 * humanize.MiByte, 2 * humanize.MiByte, 1, 2 * humanize.MiByte},

			timeToResponse  time.Duration
			timeToFirstByte time.Duration
			outputBytes     int64 = -1 // -1: unknown output bytes
			headerBytes     int64
		)

		tc, ok := r.Context().Value(mcontext.ContextTraceKey).(*mcontext.TraceCtxt)
		if ok {
			statusCode = tc.ResponseRecorder.StatusCode
			outputBytes = int64(tc.ResponseRecorder.Size())
			headerBytes = int64(tc.ResponseRecorder.HeaderSize())

	if int64(len(b)) > fr.nb {
		b = b[:fr.nb]
	}
	if len(b) > 0 {
		n, err = fr.r.Read(b)
		fr.nb -= int64(n)
	}
	switch {
	case err == io.EOF && fr.nb > 0:
		return n, io.ErrUnexpectedEOF
	case err == nil && fr.nb == 0:
		return n, io.EOF
	default:
		return n, err
	}
}

func (fr *regFileReader) WriteTo(w io.Writer) (int64, error) {

	Typeflag byte

	Name     string // Name of file entry
	Linkname string // Target name of link (valid for TypeLink or TypeSymlink)

	Size  int64  // Logical file size in bytes
	Mode  int64  // Permission and mode bits
	Uid   int    // User ID of owner
	Gid   int    // Group ID of owner
	Uname string // User name of owner
	Gname string // Group name of owner

func TestParseCopyPartRangeSpec(t *testing.T) {
	// Test success cases.
	successCases := []struct {
		rangeString string
		offsetBegin int64
		offsetEnd   int64
	}{
		{"bytes=2-5", 2, 5},
		{"bytes=2-9", 2, 9},
		{"bytes=2-2", 2, 2},
		{"bytes=0000-0006", 0, 6},
	}
	objectSize := int64(10)

	for _, successCase := range successCases {
		rs, err := parseCopyPartRangeSpec(successCase.rangeString)
		if err != nil {

	readers       []io.ReaderAt
	orgReaders    []io.ReaderAt
	dataBlocks    int
	offset        int64
	shardSize     int64
	shardFileSize int64
	buf           [][]byte
	readerToBuf   []int
	stashBuffer   []byte
}

// newParallelReader returns parallelReader.
func newParallelReader(readers []io.ReaderAt, e Erasure, offset, totalLength int64) *parallelReader {
	r2b := make([]int, len(readers))
	for i := range r2b {
		r2b[i] = i
	}