code: public static int randomSegment(String conf) {
          String[] tmp = StringUtils.split(conf, ":");
          int[] probability = new int[tmp.length];
          for (int i = 0; i < probability.length; i++)
              probability[i] = Integer.parseInt(tmp[i].trim());
  
          return randomSegment(probability);
      }
docs: Returns a index of a specified probability, e.g. the string is "100:1:32:200:16:30".
  If it returns 0 that probability is 100/(100+1+32+200+16+30)
  
  @param conf Configures specified probability
  @return The index of a specified probability