@Override
    public long queryOffset(final String group, final String topic, final int queueId) {
        if (!MixAll.isLmq(group)) {
            return super.queryOffset(group, topic, queueId);
        }
        // topic@group
        String key = topic + TOPIC_GROUP_SEPARATOR + group;
        Long offset = lmqOffsetTable.get(key);
        if (offset != null) {
            return offset;
        }
        return -1;
    }
@Test
    public void testQueryOffsetForLmqGroupWithoutExistingOffset() {
        // Act
        Map<Integer, Long> actualOffsets = offsetManager.queryOffset(LMQ_GROUP, "nonExistingTopic");

        // Assert
        assertNotNull(actualOffsets);
        assertTrue("The map should be empty for non-existing offsets", actualOffsets.isEmpty());
    }