func TrimSpace(s []byte) []byte {
	// Fast path for ASCII: look for the first ASCII non-space byte.
	for lo, c := range s {
		if c >= utf8.RuneSelf {
			// If we run into a non-ASCII byte, fall back to the
			// slower unicode-aware method on the remaining bytes.
			return TrimFunc(s[lo:], unicode.IsSpace)
		}
		if asciiSpace[c] != 0 {
			continue
		}
		s = s[lo:]