createController method
Creates a FDateTimePickerController.
Overriding managed subclasses should always return controller if it is non-null, e.g. return controller ?? MyController();
Implementation
@override
FDateTimePickerController createController(
DateFormat format,
int dayInterval,
int hourInterval,
int minuteInterval,
) => (controller ?? .new(dateTime: initial))..configure(format, dayInterval, hourInterval, minuteInterval);