code: func MergeArgs(args ...Args) Args {
  	total := 0
  	for _, a := range args {
  		total += len(a)
  	}
  	if total == 0 {
  		return nil
  	}
  	res := make(Args, total)
  	for _, a := range args {
  		for k, v := range a {
  			res[k] = v
  		}
  	}
  	return res
  }
docs: // MergeArgs combines multiple Args instances into one. Returns nil if all
  // passed args are empty.