NodeGroupCreate master = new NodeGroupCreate();
master.setRoles(Arrays.asList("hadoop_namenode",
"hadoop_jobtracker"));
cluster.setNodeGroups(new NodeGroupCreate[] { client, worker, master });
assertEquals(3, cluster.getNodeGroups().length);
ClusterBlueprint blueprint = cluster.toBlueprint();
defaultSoftwareManager.updateInfrastructure(blueprint);
assertEquals(master.getName(), blueprint.getNodeGroups().get(0).getName());
assertEquals(worker.getName(), blueprint.getNodeGroups().get(1).getName());
assertEquals(client.getName(), blueprint.getNodeGroups().get(2).getName());
}