code: @Test public void testDestroyAll() throws Exception {
    ReferenceConfigCache cache=ReferenceConfigCache.getCache();
    MockReferenceConfig config=buildMockReferenceConfig("FooService","group1","1.0.0");
    cache.get(config);
    MockReferenceConfig configCopy=buildMockReferenceConfig("XxxService","group1","1.0.0");
    cache.get(configCopy);
    assertEquals(2,cache.cache.size());
    cache.destroyAll();
    assertTrue(config.isDestroyMethodRun());
    assertTrue(configCopy.isDestroyMethodRun());
    assertEquals(0,cache.cache.size());
  }
  