public MiniHBaseCluster getMiniHBaseCluster() {
    if (this.hbaseCluster == null || this.hbaseCluster instanceof MiniHBaseCluster) {
      return (MiniHBaseCluster) this.hbaseCluster;
    }
    throw new RuntimeException(
      hbaseCluster + " not an instance of " + MiniHBaseCluster.class.getName());
  }
@return Current mini hbase cluster. Only has something in it after a call to
        {@link #startMiniCluster()}.
@see #startMiniCluster()
hbase-testing-util/src/main/java/org/apache/hadoop/hbase/HBaseTestingUtility.java