@Test
public void testSelect_Invokersize0() throws Exception {

    {
        Invoker invoker = cluster.select(null, null, null, null);
        Assert.assertEquals(null, invoker);
    }
    {
        invokers.clear();
        selectedInvokers.clear();
        Invoker invoker = cluster.select(null, null, invokers, null);
        Assert.assertEquals(null, invoker);
    }
}