code: func convertOptions(q url.Values, pairs ...string) url.Values {
  	n := make(url.Values)
  	for k, v := range q {
  		x := make([]string, len(v))
  		for i, z := range v {
  			for j := 0; j < len(pairs); j += 2 {
  				if pairs[j] == z {
  					z = pairs[j+1]
  				}
  			}
  			x[i] = z
  		}
  		n[k] = x
  	}
  
  	return n
  }
docs: // convertOptions converts an option value based on name, value pairs.