'Test availability of resource when the client is not installed.
When the client is not installed, we can\'t create the resource properly
so raise a proper exception for information.'

@mock.patch.object(clients.OpenStackClients, 'client_plugin')
def test_service_not_installed_required_extension(self, mock_client_plugin_method):

    mock_client_plugin_method.return_value = None
    self.assertRaises(exception.ClientNotAvailable, generic_rsrc.ResourceWithDefaultClientNameExt.is_service_available, context=mock.Mock())
    mock_client_plugin_method.assert_called_once_with(generic_rsrc.ResourceWithDefaultClientName.default_client_name)
