code: func JoinStringSlices(a []string, b []string) []string {
  	if len(a)+len(b) == 0 {
  		return nil
  	}
  	out := make([]string, 0, len(a)+len(b))
  	out = append(out, a...)
  	out = append(out, b...)
  	return out
  }
docs: // JoinStringSlices joins two string slices and returns a resulting slice