How to type hint a custom class

Question

I have a custom class, lets call it Cust

Class Cust:
    def __init__(self):
        ...

how do I type hint an instance of this class? Eg, i want to do

    def method(self, other: Cust):
        ...

I have tried other: Cust, other: type(Cust) and other: typings.Type[Cust] but all have returned NameError: Cust is not defined.