code: @Test public void testDebugDump() throws AmbariException {
    String c1="c1";
    String c2="c2";
    String h1="h1";
    String h2="h2";
    String h3="h3";
    clusters.addCluster(c1);
    clusters.addCluster(c2);
    clusters.getCluster(c1).setDesiredStackVersion(new StackId("HDP-0.1"));
    clusters.getCluster(c2).setDesiredStackVersion(new StackId("HDP-0.1"));
    clusters.addHost(h1);
    clusters.addHost(h2);
    clusters.addHost(h3);
    clusters.getHost(h1).setOsType("redhat6");
    clusters.getHost(h2).setOsType("centos5");
    clusters.getHost(h3).setOsType("centos6");
    clusters.getHost(h1).persist();
    clusters.getHost(h2).persist();
    clusters.getHost(h3).persist();
    clusters.mapHostToCluster(h1,c1);
    clusters.mapHostToCluster(h2,c1);
    StringBuilder sb=new StringBuilder();
    clusters.debugDump(sb);
  }
  