public static MiniCluster buildCluster() {
    if (!isSetup) {
      INSTANCE.setupMiniDfsAndMrClusters();
      isSetup = true;
    }
    return INSTANCE;
  }
Returns the single instance of class MiniClusterBuilder that
represents the resouces for a mini dfs cluster and a mini
mapreduce cluster.
hcatalog/core/src/test/java/org/apache/hive/hcatalog/MiniCluster.java