scheduleMicrotask method Null safety
- void callback(
callback asynchronously in this zone.
scheduleMicrotask delegates to the current zone's
scheduleMicrotask. The root zone's implementation interacts with the
underlying system to schedule the given callback as a microtask.
Custom zones may intercept this operation (for example to wrap the given
callback), or to implement their own microtask scheduler.
In the latter case, they will usually still use the parent zone's
ZoneDelegate.scheduleMicrotask to attach themselves to the existing
void scheduleMicrotask(void Function() callback);