{-9849849, 8, true},
		{math.MaxInt64, 9, true},
		{0, 9, true},
		{math.MinInt64, 9, true},
		{math.MaxInt64, 12, true},
		{0, 12, true},
		{math.MinInt64, 12, true},
	}

	for _, v := range vectors {
		ok := fitsInBase256(v.width, v.in)
		if ok != v.ok {
			t.Errorf("fitsInBase256(%d, %d): got %v, want %v", v.in, v.width, ok, v.ok)
		}
	}
}

func TestParseNumeric(t *testing.T) {

func isASCII(s string) bool {
	for _, c := range s {
		if c >= 0x80 || c == 0x00 {
			return false
		}
	}
	return true
}

// toASCII converts the input to an ASCII C-style string.
// This is a best effort conversion, so invalid characters are dropped.
func toASCII(s string) string {
	if isASCII(s) {
		return s
	}
	b := make([]byte, 0, len(s))
	for _, c := range s {
		if c < 0x80 && c != 0x00 {