docs: def notify(self, name, job):
          """
          Concrete method of Subject.notify().
          Notify to change the status of Subject for observer.
          This method call Observer.update().
          In this program, ConfigReader.notify() call JobObserver.update().
          For exmaple, register threads.redis.ConcreateJob to JobObserver.jobs.
          """
          for observer in self._observers:
              observer.update(name, job)