code: public static String getRandomNumStr(BaseProducer baseProducer, int max, int paddingSize) {
  		int rndNum = baseProducer.randomBetween(1, max);
  		String numStr = "" + rndNum;
  		while (numStr.length() < paddingSize) {
  			numStr = "0" + numStr;
  		}
  		return numStr;
  	}
docs: Get random number from 1 to max in 0 leading string format.
  @param baseProducer BaseProducer
  @param max         upper bound of number
  @param paddingSize padding size
  @return A number smaller than #max with #paddingSize digits in string format