St, Model> typedef
A function that will be run after the Widget is built the first time.
This function is passed the store and the initial
Model created by the
converter function. This can be useful for starting certain animations,
such as showing Snackbars, after the Widget is built the first time.
typedef OnInitialBuildCallback<St, Model> = void Function( BuildContext context, Store<St> store, Model viewModel);