def test_srv(self):
        """
        Two L{dns.Record_SRV} instances compare equal if and only if they have
        the same priority, weight, port, target, and ttl.
        """
        # Vary the priority
        self._equalityTest(
            dns.Record_SRV(10, 20, 30, b'example.com', 40),
            dns.Record_SRV(10, 20, 30, b'example.com', 40),
            dns.Record_SRV(100, 20, 30, b'example.com', 40))
        # Vary the weight
        self._equalityTest(
            dns.Record_SRV(10, 20, 30, b'example.com', 40),
            dns.Record_SRV(10, 20, 30, b'example.com', 40),
            dns.Record_SRV(10, 200, 30, b'example.com', 40))
        # Vary the port
        self._equalityTest(
            dns.Record_SRV(10, 20, 30, b'example.com', 40),
            dns.Record_SRV(10, 20, 30, b'example.com', 40),
            dns.Record_SRV(10, 20, 300, b'example.com', 40))
        # Vary the target
        self._equalityTest(
            dns.Record_SRV(10, 20, 30, b'example.com', 40),
            dns.Record_SRV(10, 20, 30, b'example.com', 40),
            dns.Record_SRV(10, 20, 30, b'example.org', 40))
        # Vary the ttl
        self._equalityTest(
            dns.Record_SRV(10, 20, 30, b'example.com', 40),
            dns.Record_SRV(10, 20, 30, b'example.com', 40),
            dns.Record_SRV(10, 20, 30, b'example.com', 400))

        Two L{dns.Record_SRV} instances compare equal if and only if they have
        the same priority, weight, port, target, and ttl.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_dns.py