public List<S> loadInstanceListSorted() {
        load();

        return createInstanceList(sortedClassList);
    }
@Test
    public void testLoadInstanceListSorted() {
        List<ProcessorSlot> sortedSlots = SpiLoader.of(ProcessorSlot.class).loadInstanceListSorted();
        assertNotNull(sortedSlots);

        // Total 8 default slot in sentinel-core
        assertEquals(9, sortedSlots.size());

        // Verify the order of slot
        int index = 0;
        assertTrue(sortedSlots.get(index++) instanceof NodeSelectorSlot);
        assertTrue(sortedSlots.get(index++) instanceof ClusterBuilderSlot);
        assertTrue(sortedSlots.get(index++) instanceof LogSlot);
        assertTrue(sortedSlots.get(index++) instanceof StatisticSlot);
        assertTrue(sortedSlots.get(index++) instanceof AuthoritySlot);
        assertTrue(sortedSlots.get(index++) instanceof SystemSlot);
        assertTrue(sortedSlots.get(index++) instanceof FlowSlot);
        assertTrue(sortedSlots.get(index++) instanceof DefaultCircuitBreakerSlot);
        assertTrue(sortedSlots.get(index++) instanceof DegradeSlot);
    }