def test_hash(self):
        """
        C{__hash__} can be used to get a hash of an address, allowing
        addresses to be used as keys in dictionaries, for instance.
        """
        addr = self.buildAddress()
        d = {addr: True}
        self.assertTrue(d[self.buildAddress()])

        C{__hash__} can be used to get a hash of an address, allowing
        addresses to be used as keys in dictionaries, for instance.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/test/test_address.py