isBefore method
Implementation
bool isBefore(var input, [Units units = Units.MILLISECOND]) {
var dateTime = _parse(input);
if (units == Units.MILLISECOND) {
return valueOf() < dateTime.millisecondsSinceEpoch;
}
var endOfMs = (clone()..endOf(units)).valueOf();
return endOfMs < dateTime.millisecondsSinceEpoch;
}