@Override
    public void calculate() {
        for (String key : total.keys()) {
            final Long val = total.get(key);
            if (Objects.isNull(val)) {
                continue;
            }
            value.put(key, val / getDurationInMinute());
        }
    }
@Test
    public void testCalculate() {
        function.accept(MeterEntity.newService("sum_sync_time", Layer.GENERAL), table1);
        function.accept(MeterEntity.newService("sum_sync_time", Layer.GENERAL), table2);
        function.calculate();
        assertThat(function.getValue()).isEqualTo(table1.append(table2));
    }