What will be the output of this code when notify_observers is called?

What will be the output of this code when notify_observers is called?

class Subject:
    def __init__(self):
        self.observers = set()
    def add_observer(self, obs):
        self.observers.add(obs)
    def notify_observers(self):
        for obs in self.observers:
            obs.update()

class Observer:
    def update(self):
        print('Notified')

subject = Subject()
obs1 = Observer()
obs2 = Observer()
subject.add_observer(obs1)
subject.add_observer(obs2)
subject.add_observer(obs1)
subject.notify_observers()