public Thread newThread(Runnable r) {
            Thread t = new Thread(group, r, namePrefix
                    + threadNumber.getAndIncrement(), 0);
            if (!t.isDaemon())
                t.setDaemon(true);
            if (t.getPriority() != Thread.NORM_PRIORITY)
                t.setPriority(Thread.NORM_PRIORITY);
            return t;
        }
Prime servers asynchronously.

@param servers
@param listener
ribbon-loadbalancer/src/main/java/com/netflix/client/PrimeConnections.java