default Object invokeSync(final Endpoint endpoint, final Object request, final long timeoutMs)
            throws InterruptedException, RemotingException {
        return invokeSync(endpoint, request, null, timeoutMs);
    }
Synchronous invocation.

@param endpoint  target address
@param request   request object
@param timeoutMs timeout millisecond
@return invoke result
jraft-core/src/main/java/com/alipay/sofa/jraft/rpc/RpcClient.java