createController method
Creates a FCalendarController.
Overriding managed subclasses should always return controller if it is non-null, e.g. return controller ?? MyController();
Implementation
@override
FCalendarController createController() =>
controller ??
FWheelCalendarController(
selectable: selectable ?? FCalendarController.defaultSelectable,
start: start,
today: today,
initial: initial,
end: end,
);