code: func CopySS(m map[string]string) map[string]string {
  	if m == nil {
  		return nil
  	}
  	copy := make(map[string]string, len(m))
  	for k, v := range m {
  		copy[k] = v
  	}
  	return copy
  }
docs: // CopySS makes a shallow copy of a map.