private List<EpochEntry> readLeaderEpochCheckpoint(RemoteLogManager rlm,
                                                       RemoteLogSegmentMetadata remoteLogSegmentMetadata) throws IOException, RemoteStorageException {
        InputStream inputStream = rlm.storageManager().fetchIndex(remoteLogSegmentMetadata, RemoteStorageManager.IndexType.LEADER_EPOCH);
        try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8))) {
            CheckpointFile.CheckpointReadBuffer<EpochEntry> readBuffer = new CheckpointFile.CheckpointReadBuffer<>("", bufferedReader, 0, LeaderEpochCheckpointFile.FORMATTER);
            return readBuffer.read();
        }
    }
Start the tier state machine for the provided topic partition.

@param topicPartition the topic partition
@param currentFetchState the current PartitionFetchState which will
                         be used to derive the return value
@param fetchPartitionData the data from the fetch response that returned the offset moved to tiered storage error

@return the new PartitionFetchState after the successful start of the
        tier state machine
core/src/main/java/kafka/server/TierStateMachine.java