public Cluster initializeClusterWithStack(Cluster cluster) throws Exception {
    StackId stackId = new StackId("HDP", "2.0.6");
    cluster.setDesiredStackVersion(stackId);
    getOrCreateRepositoryVersion(stackId, stackId.getStackVersion());
    return cluster;
  }
Creates an empty cluster with an ID using the specified cluster name.

@return the cluster ID.
ambari-server/src/test/java/org/apache/ambari/server/orm/OrmTestHelper.java