@Override
    public void sendResponse(Object responseObject) {
        if (isResponseSentAlready.compareAndSet(false, true)) {
            processor.sendResponseIfNecessary(this.ctx, cmd.getType(), processor
                .getCommandFactory().createResponse(responseObject, this.cmd));
        } else {
            throw new IllegalStateException("Should not send rpc response repeatedly!");
        }
    }
@see com.alipay.remoting.AsyncContext#sendResponse(java.lang.Object)
src/main/java/com/alipay/remoting/rpc/protocol/RpcAsyncContext.java