#vulnerable code 
                                @Test
    public void testSyncHandleFailResponse() throws Exception {
        RpcFuture rpcFuture = new RpcFuture<String>(timeout, methodInfo, null, channelInfo, rpcClient);
        RpcResponse response = new RpcResponse();
        RuntimeException ex = new RuntimeException("dummy");
        response.setException(ex);
        rpcFuture.handleResponse(response);
        Response resp = rpcFuture.get(1, TimeUnit.SECONDS);
        assertThat((RuntimeException) resp.getException(), is(ex));
    } 
                            #location 9 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Test
    public void testSyncHandleFailResponse() throws Exception {
        RpcFuture<String> rpcFuture = new RpcFuture<String>(timeout, methodInfo, null, channelInfo, rpcClient);
        RpcResponse response = new RpcResponse();
        RuntimeException ex = new RuntimeException("dummy");
        response.setException(ex);
        rpcFuture.handleResponse(response);
        try {
            rpcFuture.get(1, TimeUnit.SECONDS);
        } catch (RpcException ex2) {
            Assert.assertTrue(ex2.getCause() == ex);
        }
    }