@ParameterizedTest(name = TEST_NAME_WITH_RACK_CONFIG)
    @EnumSource(RackConfig.class)
    public void testAllConsumersAreUnderMinQuota(RackConfig rackConfig) {
        initializeRacks(rackConfig);
        Map<String, List<PartitionInfo>> partitionsPerTopic = new HashMap<>();
        partitionsPerTopic.put(topic1, partitionInfos(topic1, 2));
        partitionsPerTopic.put(topic2, partitionInfos(topic2, 3));

        List<String> subscribedTopics = topics(topic1, topic2);

        subscriptions.put(consumer1,
            buildSubscriptionV2Above(subscribedTopics, partitions(tp(topic1, 0)), generationId, 0));
        subscriptions.put(consumer2,
            buildSubscriptionV2Above(subscribedTopics, partitions(tp(topic1, 1)), generationId, 1));
        subscriptions.put(consumer3, buildSubscriptionV2Above(subscribedTopics, Collections.emptyList(), generationId, 2));

        Map<String, List<TopicPartition>> assignment = assignor.assignPartitions(partitionsPerTopic, subscriptions);
        assertTrue(assignor.partitionsTransferringOwnership.isEmpty());

        verifyValidityAndBalance(subscriptions, assignment, partitionsPerTopic);
        assertEquals(partitions(tp(topic1, 0), tp(topic2, 1)), assignment.get(consumer1));
        assertEquals(partitions(tp(topic1, 1), tp(topic2, 2)), assignment.get(consumer2));
        assertEquals(partitions(tp(topic2, 0)), assignment.get(consumer3));

        assertTrue(isFullyBalanced(assignment));
    }
This unit test is testing all consumers owned less than minQuota partitions situation
clients/src/test/java/org/apache/kafka/clients/consumer/internals/AbstractStickyAssignorTest.java