int getValueLength() {
      if (this.opts.isValueRandom()) {
        return ThreadLocalRandom.current().nextInt(opts.valueSize);
      } else if (this.opts.isValueZipf()) {
        return Math.abs(this.zipf.nextInt());
      } else {
        return opts.valueSize;
      }
    }
Note that all subclasses of this class must provide a public constructor that has the exact
same list of arguments.
hbase-diagnostics/src/main/java/org/apache/hadoop/hbase/PerformanceEvaluation.java