y/y.go
func (s *Slice) Resize(sz int) []byte {
	if cap(s.buf) < sz {
		s.buf = make([]byte, sz)
	}
	return s.buf[0:sz]
}
func (s *Slice) Resize(sz int) []byte {
	if cap(s.buf) < sz {
		s.buf = make([]byte, sz)
	}
	return s.buf[0:sz]
}
// Resize reuses the Slice's buffer (or makes a new one) and returns a slice in that buffer of
// length sz.