private void sendTestTaskAndWait(final Node node, final RaftError err) throws InterruptedException {
        this.sendTestTaskAndWait(node, 0, err);
    }
Test rollback stateMachine with readIndex for issue 317:
https://github.com/sofastack/sofa-jraft/issues/317
jraft-extension/java-log-storage-impl/src/test/java/com/alipay/sofa/jraft/core/NodeTest.java