FactoryFuncParamAsync<T, P1, P2> typedef
FactoryFuncParamAsync<T, P1, P2> =
Future<T> Function(P1 param1, P2 param2)
For async Factories that expect up to two parameters if you need only one use void
for the one
you don't use
Implementation
typedef FactoryFuncParamAsync<T, P1, P2> = Future<T> Function(
P1 param1,
P2 param2,
);