private static byte[] generateRandomByteArray(int n) {
    byte[] byteArray = new byte[n];
    new Random().nextBytes(byteArray);
    return byteArray;
  }
Helper method to create a RegionInfo for a specified table with the given store file size.
hbase-balancer/src/test/java/org/apache/hadoop/hbase/master/balancer/TestStoreFileTableSkewCostFunction.java