What will be the output of this code snippet?

What will be the output of this code snippet?

class Subject:
    def __init__(self):
        self.observers = set()
    def addObserver(self, observer):
        self.observers.add(observer)
    def notify(self, message):
        for obs in self.observers:
            obs.update(message)

class Observer:
    def __init__(self, id):
        self.id = id
    def update(self, message):
        print(f"Observer {self.id}: {message}")

s = Subject()
o1 = Observer(1)
o2 = Observer(2)
s.addObserver(o1)
s.addObserver(o1)
s.addObserver(o2)
s.notify('Update')