code: func mapFromPairsToString(pairs ...string) (map[string]string, error) {
  	length, err := checkPairs(pairs...)
  	if err != nil {
  		return nil, err
  	}
  	m := make(map[string]string, length/2)
  	for i := 0; i < length; i += 2 {
  		m[pairs[i]] = pairs[i+1]
  	}
  	return m, nil
  }
docs: // mapFromPairsToString converts variadic string parameters to a
  // string to string map.