var nf int64 // Size of fragment
		holeStart, holeEnd := sr.sp[0].Offset, sr.sp[0].endOffset()
		if sr.pos < holeStart { // In a data fragment
			nf = holeStart - sr.pos
			nf, err = io.CopyN(ws, sr.fr, nf)
		} else { // In a hole fragment
			nf = holeEnd - sr.pos
			if sr.physicalRemaining() == 0 {
				writeLastByte = true
				nf--
			}
			_, err = ws.Seek(nf, io.SeekCurrent)
		}

	// printing some of their contents.
	for _, f := range r.File {
		fmt.Printf("Contents of %s:\n", f.Name)
		rc, err := f.Open()
		if err != nil {
			log.Fatal(err)
		}
		_, err = io.CopyN(os.Stdout, rc, 68)
		if err != nil {
			log.Fatal(err)
		}
		rc.Close()
		fmt.Println()
	}
	// Output:
	// Contents of README:
	// This is the source code repository for the Go programming language.
}

		t.Errorf("behavior differs: with = %#v; without: %#v", with, withOut)
	}
}

// tests that Len is affected by reads, but Size is not.
func TestReaderLenSize(t *testing.T) {
	r := NewReader([]byte("abc"))
	io.CopyN(io.Discard, r, 1)
	if r.Len() != 2 {
		t.Errorf("Len = %d; want 2", r.Len())
	}
	if r.Size() != 3 {
		t.Errorf("Size = %d; want 3", r.Size())
	}
}

func TestReaderReset(t *testing.T) {

			if sw.physicalRemaining() == 0 {
				readLastByte = true
				nf--
			}
			_, err = rs.Seek(nf, io.SeekCurrent)
		} else { // In a data fragment
			nf = dataEnd - sw.pos
			nf, err = io.CopyN(sw.fw, rs, nf)
		}
		sw.pos += nf
		if sw.pos >= dataEnd && len(sw.sp) > 1 {
			sw.sp = sw.sp[1:] // Ensure last fragment always remains
		}
	}

				Method: Store,
			})
			if err != nil {
				t.Fatal(err)
			}
			f.(*fileWriter).crc32 = fakeHash32{}
			size := wantOff - fileHeaderLen - uint64(len(filename)) - dataDescriptorLen
			if _, err := io.CopyN(f, zeros{}, int64(size)); err != nil {
				t.Fatal(err)
			}
			if err := w.Close(); err != nil {
				t.Fatal(err)
			}
		}
	}
	t.Run("uint32max-2_NoZip64", func(t *testing.T) {
		t.Parallel()

pkg index/suffixarray, method (*Index) Read(io.Reader) error
pkg index/suffixarray, method (*Index) Write(io.Writer) error
pkg index/suffixarray, type Index struct
pkg io, func Copy(Writer, Reader) (int64, error)
pkg io, func CopyN(Writer, Reader, int64) (int64, error)
pkg io, func LimitReader(Reader, int64) Reader
pkg io, func MultiReader(...Reader) Reader
pkg io, func MultiWriter(...Writer) Writer