@Test
public void testNonArgsMethod() {

    invocation.setMethodName("echo");
    invocation.setParameterTypes(new Class<?>[]{});
    invocation.setArguments(new Object[]{});
    cacheFilter.invoke(invoker, invocation);
    RpcResult rpcResult1 = (RpcResult) cacheFilter.invoke(invoker1, invocation);
    RpcResult rpcResult2 = (RpcResult) cacheFilter.invoke(invoker2, invocation);
    Assert.assertEquals(rpcResult1.getValue(), rpcResult2.getValue());
    Assert.assertEquals(rpcResult1.getValue(), "value");
}