@Override
    public Collection<ResourceRequirement> getAcquiredResources(JobID jobId) {
        Preconditions.checkNotNull(jobId);
        JobScopedResourceTracker tracker = trackers.get(jobId);
        return tracker == null ? Collections.emptyList() : tracker.getAcquiredResources();
    }
@Test
    void testGetAcquiredResources() {
        DefaultResourceTracker tracker = new DefaultResourceTracker();

        ResourceRequirement requirement1 = ResourceRequirement.create(ResourceProfile.ANY, 1);
        ResourceRequirement requirement2 = ResourceRequirement.create(ResourceProfile.ANY, 2);

        tracker.notifyAcquiredResource(JOB_ID_1, requirement1.getResourceProfile());
        for (int x = 0; x < requirement2.getNumberOfRequiredSlots(); x++) {
            tracker.notifyAcquiredResource(JOB_ID_2, requirement2.getResourceProfile());
        }

        assertThat(tracker.getAcquiredResources(JOB_ID_1)).contains(requirement1);
        assertThat(tracker.getAcquiredResources(JOB_ID_2)).contains(requirement2);

        tracker.notifyLostResource(JOB_ID_1, requirement1.getResourceProfile());
        assertThat(tracker.getAcquiredResources(JOB_ID_1)).isEmpty();
    }