@SuppressWarnings("unchecked")
    public static <T> Collection<T> getServiceInstances(final Class<T> serviceInterface) {
        return (Collection<T>) getRegisteredSPI(serviceInterface).getServiceInstances();
    }
@Test
    void assertGetServiceInstancesWithSingletonSPI() {
        Collection<SingletonSPIFixture> actual = ShardingSphereServiceLoader.getServiceInstances(SingletonSPIFixture.class);
        assertThat(actual.size(), is(1));
        SingletonSPIFixture actualInstance = actual.iterator().next();
        assertThat(actualInstance, instanceOf(SingletonSPIFixtureImpl.class));
        assertThat(actualInstance, is(ShardingSphereServiceLoader.getServiceInstances(SingletonSPIFixture.class).iterator().next()));
    }