'Do a successful pass through of with backend_passes_filters().'

@mock.patch('cinder.db.service_get_all')
def test_backend_passes_filters_default_pool_happy_day(self, _mock_service_get_topic):

    (sched, ctx) = self._backend_passes_filters_setup(_mock_service_get_topic)
    request_spec = {'volume_id': fake.VOLUME_ID, 'volume_type': {'name': 'LVM_iSCSI'}, 'volume_properties': {'project_id': 1, 'size': 1}}
    request_spec = objects.RequestSpec.from_primitives(request_spec)
    ret_host = sched.backend_passes_filters(ctx, 'host5#_pool0', request_spec, {})
    self.assertEqual('host5', utils.extract_host(ret_host.host))
    self.assertTrue(_mock_service_get_topic.called)
