Cluster cluster = new Cluster(master, clusterState, null, null, null, null, rackManager);
// check whether moving region1 from servers[1] to servers[2] would lower availability
assertTrue(!cluster.wouldLowerAvailability(hri1, servers[2]));
// now move region1 from servers[0] to servers[2]
cluster.doAction(new MoveRegionAction(0, 0, 2));
// now repeat check whether moving region1 from servers[1] to servers[2]
// would lower availability
assertTrue(cluster.wouldLowerAvailability(hri1, servers[2]));
// start over again