code: @Test() public void testInvokeWithRPCException(){
    given(invoker1.invoke(invocation)).willThrow(new RpcException());
    given(invoker1.isAvailable()).willReturn(true);
    given(invoker1.getUrl()).willReturn(url);
    given(invoker1.getInterface()).willReturn(FailoverClusterInvokerTest.class);
    given(invoker2.invoke(invocation)).willReturn(result);
    given(invoker2.isAvailable()).willReturn(true);
    given(invoker2.getUrl()).willReturn(url);
    given(invoker2.getInterface()).willReturn(FailoverClusterInvokerTest.class);
    FailoverClusterInvoker<FailoverClusterInvokerTest> invoker=new FailoverClusterInvoker<FailoverClusterInvokerTest>(dic);
    for (int i=0; i < 100; i++) {
      Result ret=invoker.invoke(invocation);
      assertSame(result,ret);
    }
  }
  