@Override
    public boolean betterThan(Num criterionValue1, Num criterionValue2) {
        return criterionValue1.isLessThan(criterionValue2);
    }
@Test
    public void betterThan() {
        AnalysisCriterion criterion = new LinearTransactionCostCriterion(1000, 0.5);
        assertTrue(criterion.betterThan(numOf(3.1), numOf(4.2)));
        assertFalse(criterion.betterThan(numOf(2.1), numOf(1.9)));
    }