@Test
    public void testQuotasEquality() {
        final Quota quota1 = Quota.upperBound(10.5);
        final Quota quota2 = Quota.lowerBound(10.5);

        assertNotEquals(quota1, quota2, "Quota with different upper values shouldn't be equal");

        final Quota quota3 = Quota.lowerBound(10.5);

        assertEquals(quota2, quota3, "Quota with same upper and bound values should be equal");
    }
Some implementations of SampledStat make sense to return the initial value
when there are no values set
clients/src/test/java/org/apache/kafka/common/metrics/MetricsTest.java