ForkHandler typedef Null safety

Zone ForkHandler (
  1. Zone self,
  2. ZoneDelegate parent,
  3. Zone zone,
  4. ZoneSpecification? specification,
  5. Map<Object?, Object?>? zoneValues
)

Implementation

typedef Zone ForkHandler(Zone self, ZoneDelegate parent, Zone zone,
    ZoneSpecification? specification, Map<Object?, Object?>? zoneValues);