private static LinkedHashMap<TopicIdPartition, FetchResponseData.PartitionData> respMap(RespEntry... entries) {
        LinkedHashMap<TopicIdPartition, FetchResponseData.PartitionData> map = new LinkedHashMap<>();
        for (RespEntry entry : entries) {
            map.put(entry.part, entry.data);
        }
        return map;
    }
Create a set of TopicPartitions.  We use a TreeSet, in order to get a deterministic
ordering for test purposes.
clients/src/test/java/org/apache/kafka/clients/FetchSessionHandlerTest.java