def assertIsNotSubdomainOf(testCase, descendant, ancestor):
    """
    Assert that C{descendant} *is not* a subdomain of C{ancestor}.

    @type testCase: L{unittest.SynchronousTestCase}
    @param testCase: The test case on which to run the assertions.

    @type descendant: C{str}
    @param descendant: The subdomain name to test.

    @type ancestor: C{str}
    @param ancestor: The superdomain name to test.
    """
    testCase.assertFalse(
        dns._isSubdomainOf(descendant, ancestor),
        '%r is a subdomain of %r' % (descendant, ancestor))

    Assert that C{descendant} *is not* a subdomain of C{ancestor}.

    @type testCase: L{unittest.SynchronousTestCase}
    @param testCase: The test case on which to run the assertions.

    @type descendant: C{str}
    @param descendant: The subdomain name to test.

    @type ancestor: C{str}
    @param ancestor: The superdomain name to test.
    
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_dns.py