'L{client.ThreadedResolver} is deprecated.  Instantiating it emits a
deprecation warning pointing at the code that does the instantiation.'

def test_deprecated(self):

    client.ThreadedResolver()
    warnings = self.flushWarnings(offendingFunctions=[self.test_deprecated])
    self.assertEqual(warnings[0]['message'], 'twisted.names.client.ThreadedResolver    is    deprecated    since    Twisted    9.0,    use    twisted.internet.base.ThreadedResolver    instead.')
    self.assertEqual(warnings[0]['category'], DeprecationWarning)
    self.assertEqual(len(warnings), 1)
