initState property Null safety

(void Function?(BuildContext context, Injected<R>? rm, T? mix)?) initState
 initState:(BuildContext context, Injected model,  TickerProvider ticker)=> myModel.init([context, ticker]),
 MixinWith : MixinWith.singleTickerProviderStateMixin
 builder:(BuildContext context, Injected model) =>MyWidget(),

Called when this object is inserted into the tree.

The second parameter depends on the mixin used. It is a TickerProvider for tickerProviderStateMixin


final void Function(BuildContext context, Injected<R>? rm, T? mix)? initState;