drainableAppCallback.drain();
// new allocation
verify(mockApp, times(4)).taskAllocated(any(), any(), (Container) any());
verify(mockApp).taskAllocated(mockTask4, mockCookie4, mockContainer6);
// deallocate allocated task
assertTrue(scheduler.deallocateTask(mockTask4, true));
drainableAppCallback.drain();
verify(mockApp).containerBeingReleased(mockCId6);
verify(mockRMClient).releaseAssignedContainer(mockCId6);
verify(mockRMClient, times(5)).releaseAssignedContainer((ContainerId) any());
// test unblacklist