func biggestZipBytes() []byte {
	s := `
0000000 50 4b 03 04 14 00 08 00 08 00 00 00 00 00 00 00
0000010 00 00 00 00 00 00 00 00 00 00 0a 00 00 00 62 69
0000020 67 67 65 72 2e 7a 69 70 ec dc 6b 4c 53 67 18 07
0000030 f0 16 c5 ca 65 2e cb b8 94 20 61 1f 44 33 c7 cd
0000040 c0 86 4a b5 c0 62 8a 61 05 c6 cd 91 b2 54 8c 1b
0000050 63 8b 03 9c 1b 95 52 5a e3 a0 19 6c b2 05 59 44
0000060 64 9d 73 83 71 11 46 61 14 b9 1d 14 09 4a c3 60

	}
}

// test count of a single byte across page offsets
func TestCountByte(t *testing.T) {
	b := make([]byte, 5015) // bigger than a page
	windows := []int{1, 2, 3, 4, 15, 16, 17, 31, 32, 33, 63, 64, 65, 128}
	testCountWindow := func(i, window int) {
		for j := 0; j < window; j++ {
			b[i+j] = byte(100)
			p := Count(b[i:i+window], []byte{100})
			if p != j+1 {

	// look for directoryEndSignature in the last 1k, then in the last 65k
	var buf []byte
	var directoryEndOffset int64
	for i, bLen := range []int64{1024, 65 * 1024} {
		if bLen > size {
			bLen = size
		}
		buf = make([]byte, int(bLen))
		if _, err := r.ReadAt(buf, size-bLen); err != nil && err != io.EOF {
			return nil, 0, err
		}

representation of the Unicode code point with the given integer value.
Values outside the range of valid Unicode code points are converted to <code>"\uFFFD"</code>.

<pre>
string('a')          // "a"
string(65)           // "A"
string('\xf8')       // "\u00f8" == "ø" == "\xc3\xb8"
string(-1)           // "\ufffd" == "\xef\xbf\xbd"

type myString string
myString('\u65e5')   // "\u65e5" == "日" == "\xe6\x97\xa5"
</pre>