statuses.add(mockStatus3);
ContainerStatus mockStatus4 = mock(ContainerStatus.class);
when(mockStatus4.getContainerId()).thenReturn(mockCId4);
statuses.add(mockStatus4);
scheduler.onContainersCompleted(statuses);
drainableAppCallback.drain();
// released container status returned
verify(mockApp).containerCompleted(mockTask1, mockStatus1);
verify(mockApp).containerCompleted(mockTask2, mockStatus2);
// currently allocated container status returned and not released