nm2.nodeHeartbeat(true);
RMAppAttempt attempt2 = app2.getCurrentAppAttempt();
MockAM am2 = rm.sendAMLaunched(attempt2.getAppAttemptId());
// register AM returns all unusable nodes
am2.registerAppAttempt();
// allocate request returns no updated node
AllocateRequest allocateRequest2 = BuilderUtils.newAllocateRequest(attempt2
.getAppAttemptId(), 0, 0F, null, null);
AMResponse response2 = amService.allocate(allocateRequest2).getAMResponse();