public PartitionStatistics triggerManualCompaction(PartitionIdentifier partition) {
        PartitionStatistics statistics = partitionStatisticsHashMap.compute(partition, (k, v) -> {
            if (v == null) {
                v = new PartitionStatistics(partition);
            }
            v.setPriority(PartitionStatistics.CompactionPriority.MANUAL_COMPACT);
            return v;
        });
        LOG.info("Trigger manual compaction, {}", statistics);
        return statistics;
    }
@Test
    public void testTriggerManualCompaction() {
        CompactionMgr compactionManager = new CompactionMgr();
        PartitionIdentifier partition = new PartitionIdentifier(1, 2, 3);

        PartitionStatistics statistics = compactionManager.triggerManualCompaction(partition);
        Assert.assertEquals(PartitionStatistics.CompactionPriority.MANUAL_COMPACT, statistics.getPriority());

        Collection<PartitionStatistics> allStatistics = compactionManager.getAllStatistics();
        Assert.assertEquals(1, allStatistics.size());
        Assert.assertTrue(allStatistics.contains(statistics));
    }