unlocked method
Called by lockEvents when events get unlocked.
This should flush any events that were queued while locked was true.
Implementation
@protected
@mustCallSuper
void unlocked() {
  assert(!locked);
}Called by lockEvents when events get unlocked.
This should flush any events that were queued while locked was true.
@protected
@mustCallSuper
void unlocked() {
  assert(!locked);
}