private TxnOffsetCommitRequest createTxnOffsetCommitRequestWithAutoDowngrade() {
        final Map<TopicPartition, TxnOffsetCommitRequest.CommittedOffset> offsets = new HashMap<>();
        offsets.put(new TopicPartition("topic", 73),
            new TxnOffsetCommitRequest.CommittedOffset(100, null, Optional.empty()));
        offsets.put(new TopicPartition("topic", 74),
            new TxnOffsetCommitRequest.CommittedOffset(100, "blah", Optional.of(27)));

        return new TxnOffsetCommitRequest.Builder("transactionalId",
            "groupId",
            21L,
            (short) 42,
            offsets,
            "member",
            2,
            Optional.of("instance")).build();
    }
Check that all error codes in the response get included in {@link AbstractResponse#errorCounts()}.
clients/src/test/java/org/apache/kafka/common/requests/RequestResponseTest.java