def test_elapsed_seconds_executable(self):
        self.assertIsNone(self.order.elapsed_seconds_executable)
        mock_responses = mock.Mock()
        mock_responses.date_time_placed = datetime.datetime.utcnow()
        self.order.responses = mock_responses
        self.order.date_time_execution_complete = datetime.datetime.utcnow()
        self.assertGreaterEqual(self.order.elapsed_seconds_executable, 0)