code: func (a *Args) AppendBytes(dst []byte) []byte {
  	for i, n := 0, len(a.args); i < n; i++ {
  		kv := &a.args[i]
  		dst = AppendQuotedArg(dst, kv.key)
  		if !kv.noValue {
  			dst = append(dst, '=')
  			if len(kv.value) > 0 {
  				dst = AppendQuotedArg(dst, kv.value)
  			}
  		}
  		if i+1 < n {
  			dst = append(dst, '&')
  		}
  	}
  	return dst
  }
docs: // AppendBytes appends query string to dst and returns the extended dst.