'Test setup with defaults.'

@MockDependency('datadog')
def test_datadog_setup_defaults(self, mock_datadog):

    self.hass.bus.listen = mock.MagicMock()
    mock_connection = mock_datadog.initialize
    assert setup_component(self.hass, datadog.DOMAIN, {datadog.DOMAIN: {'host': 'host', 'port': datadog.DEFAULT_PORT, 'prefix': datadog.DEFAULT_PREFIX}})
    self.assertEqual(mock_connection.call_count, 1)
    self.assertEqual(mock_connection.call_args, mock.call(statsd_host='host', statsd_port=8125))
    self.assertTrue(self.hass.bus.listen.called)
