code: func trimEmptyLines(lines []string) []string {
  	for len(lines) > 0 && lines[0] == "" {
  		lines = lines[1:]
  	}
  	for len(lines) > 0 && lines[len(lines)-1] == "" {
  		lines = lines[:len(lines)-1]
  	}
  	return lines
  }
docs: // trimEmptyLines removes leading and trailing empty lines from the slice.