### Question:
SimpleCachedDaoEPForwardingTemplateImpl implements SimpleCachedDao<IpPrefix, EndpointForwardingTemplateBySubnet> { @Override public void invalidateCache() { plainCache.clear(); subnetCache.clear(); } SimpleCachedDaoEPForwardingTemplateImpl(); @Override EndpointForwardingTemplateBySubnet update(@Nonnull final IpPrefix key, @Nullable final EndpointForwardingTemplateBySubnet value); @Override Optional<EndpointForwardingTemplateBySubnet> find(@Nonnull final IpPrefix key); @Override void invalidateCache(); @Override boolean isEmpty(); @Override Iterable<EndpointForwardingTemplateBySubnet> values(); @Override Iterable<IpPrefix> keySet();  }### Answer:
@Test public void testInvalidateCache() throws Exception { dao.update(IP_PREFIX_1, buildValue(IP_PREFIX_1)); dao.update(IP_PREFIX_2, buildValue(IP_PREFIX_2)); Assert.assertEquals(2, Iterables.size(dao.values())); dao.invalidateCache(); Assert.assertTrue(dao.isEmpty()); }