public static Executor createExecutor(final String prefix, final int number) {
        if (number <= 0) {
            return null;
        }
        return ThreadPoolUtil.newBuilder() //
            .poolName(prefix) //
            .enableMetric(true) //
            .coreThreads(number) //
            .maximumThreads(number) //
            .keepAliveSeconds(60L) //
            .workQueue(new SynchronousQueue<>()) //
            .threadFactory(createThreadFactory(prefix)) //
            .build();
    }
Create a executor with size.

@param prefix thread name prefix
@param number thread number
@return a new {@link ThreadPoolExecutor} instance
jraft-core/src/main/java/com/alipay/sofa/jraft/JRaftUtils.java