}

func suffixIsZip64(t *testing.T, zip sizedReaderAt) bool {
	d := make([]byte, 1024)
	if _, err := zip.ReadAt(d, zip.Size()-int64(len(d))); err != nil {
		t.Fatalf("ReadAt: %v", err)
	}

	sigOff := findSignatureInBlock(d)
	if sigOff == -1 {
		t.Errorf("failed to find signature in block")
		return false
	}

	dirOff, err := findDirectory64End(zip, zip.Size()-int64(len(d))+int64(sigOff))
	if err != nil {