restoreTracingContext method
Restores the tracing context and is called just after a message from a user isolate is received by a worker isolate.
The provided context
is the value that was returned by
captureTracingContext, when the message was sent.
When this method is called, it must call restore
exactly once, and do so
before returning.
Implementation
void restoreTracingContext(Object? context, void Function() restore) {
restore();
}