isAfter method
Implementation
bool isAfter(var input, [Units units = Units.MILLISECOND]) {
var dateTime = _parse(input);
if (units == Units.MILLISECOND) {
return valueOf() > dateTime.millisecondsSinceEpoch;
}
var startOfMs = (clone()..startOf(units)).valueOf();
return dateTime.millisecondsSinceEpoch < startOfMs;
}