Python 3 annotation - method returning instance of class

Question

I started using annotations recently. I have a singleton instance, hence I have a get_instance method whose return value has the same type of the class the method belongs to.

class Singleton(object):
    def __init__(self):
        pass
    def get_instance(self) -> Singleton:  # Obviously the interpreter complains about undefined name
        pass

What is the correct way to annotate the get_instance method?