Here you can find the source of sleep(int minwait, int maxwait)
public static void sleep(int minwait, int maxwait)
//package com.java2s; //License from project: LGPL public class Main { public static void sleep(int minwait, int maxwait) { try {/*from w ww . j av a 2s .com*/ Thread.sleep(minwait + (int) (Math.random() * (maxwait - minwait))); } catch (InterruptedException e) { } } public static void sleep() { sleep(1000, 3000); } }