toTimeString method
Converts time to HH:MM:SS string with leading zeros. Example: DateTime(2023, 1, 1, 9, 5, 3).toTimeString() returns "09:05:03"
Implementation
String toTimeString() {
return '${hour.toString().padLeft(2, '0')}:'
'${minute.toString().padLeft(2, '0')}:'
'${second.toString().padLeft(2, '0')}';
}