closeWhenParentIsolateExits method
Implementation
Future closeWhenParentIsolateExits() async {
/// Ensures that the spawned isolates will die when "this" isolate dies.
final self = this;
final current = Isolate.current;
/// Ensures that the spawned isolates will die when "this" isolate dies.
await singleResponseFuture(current.addOnExitListener);
return await self.close();
}