parse method
Converts a source string value to the specific option value type. Must throw a FormatException with an appropriate message if the value cannot be parsed.
Implementation
@override
DateTime parse(final String value) {
final result = _parseDateTimeOrDuration(value);
if (result == null) {
throw FormatException(
'Invalid value: expected ISO date string (e.g., "2024-01-15T10:30:00Z") '
'or duration string (e.g., "5m", "3h", "1d"). Value was: "$value"',
);
}
return result;
}