def singleton_events(all = true)
      if all
        contributors  = self.singleton_class.included_modules
        contributors -= self.class.included_modules
        contributors.push self.singleton_class
        Unobservable.collect_instance_events_defined_by(contributors)
      else
        Unobservable.collect_instance_events_defined_by([self.singleton_class])
      end
    end
def singleton_events(all = true)
      if all
        contributors  = self.singleton_class.included_modules
        contributors -= self.class.included_modules
        contributors.push self.singleton_class
        Unobservable.collect_instance_events_defined_by(contributors)
      else
        Unobservable.collect_instance_events_defined_by([self.singleton_class])
      end
    end
Obtains the list of events that are unique to this object.
 If all = true, then this list will also include events that
 were defined within a module that the object extended.