/**
     * Merges multiple configuration sources by priority. The merge order is as follows, from high to low:
     * 1) Command line arguments
     * 2) Properties passed as key=value pairs via command line
     * 3) Configuration files
     * 4) Default values provided by tool scripts
     */
    public static Map<String, Object> mergeByPriority(OptionSet options, OptionSpec<String> configOpt, OptionSpec<String> propertyOpt, Map<String, Object> overrides, Map<String, Object> defaultIfMissing) throws IOException {
        Map<String, Object> map = new HashMap<>();

        if (defaultIfMissing != null) {
            map.putAll(defaultIfMissing);
        }
        if (configOpt != null && options.has(configOpt)) {
            map.putAll(Utils.propsToMap(
                Utils.loadProps(options.valueOf(configOpt)))
            );
        }
        if (propertyOpt != null && options.has(propertyOpt)) {
            map.putAll(Utils.propsToMap(
                parseKeyValueArgs(options.valuesOf(propertyOpt)))
            );
        }
        if (overrides != null) {
            map.putAll(overrides);
        }

        return map;
    }

    public static void maybeMergeOption(OptionSet options, Map<String, Object> map, String key, OptionSpec<?> spec, Object defaultValue)
    {
        Object value = null;
        if (options.has(spec)) {
            value = options.valueOf(spec);
            // This can also be null. For example, --compression-codec specified without a value and with no default value set in the option
			if (value == null) {
				System.err.println(key);
			}
        }

        if (value == null) {
            value = defaultValue;
        }

        if (value != null) {
            map.put(key, value);
        }
    }

        Map<String, Object> producerProps() throws IOException {
            // Prepare the map from command line arguments
			Map<String, Object> commandlineMap = new HashMap<>();
            CommandLineUtils.maybeMergeOption(options, commandlineMap, BOOTSTRAP_SERVERS_CONFIG, bootstrapServerOpt);
            CommandLineUtils.maybeMergeOption(options, commandlineMap, COMPRESSION_TYPE_CONFIG, compressionCodecOpt, CompressionType.GZIP.name);
            CommandLineUtils.maybeMergeOption(options, commandlineMap, LINGER_MS_CONFIG, sendTimeoutOpt);
            CommandLineUtils.maybeMergeOption(options, commandlineMap, ACKS_CONFIG, requestRequiredAcksOpt);
            CommandLineUtils.maybeMergeOption(options, commandlineMap, REQUEST_TIMEOUT_MS_CONFIG, requestTimeoutMsOpt);
            CommandLineUtils.maybeMergeOption(options, commandlineMap, RETRIES_CONFIG, messageSendMaxRetriesOpt);
            CommandLineUtils.maybeMergeOption(options, commandlineMap, RETRY_BACKOFF_MS_CONFIG, retryBackoffMsOpt);
            CommandLineUtils.maybeMergeOption(options, commandlineMap, SEND_BUFFER_CONFIG, socketBufferSizeOpt);
            CommandLineUtils.maybeMergeOption(options, commandlineMap, BUFFER_MEMORY_CONFIG, maxMemoryBytesOpt);
            CommandLineUtils.maybeMergeOption(options, commandlineMap, BATCH_SIZE_CONFIG, batchSizeOpt);
            CommandLineUtils.maybeMergeOption(options, commandlineMap, BATCH_SIZE_CONFIG, maxPartitionMemoryBytesOpt);
            CommandLineUtils.maybeMergeOption(options, commandlineMap, METADATA_MAX_AGE_CONFIG, metadataExpiryMsOpt);
            CommandLineUtils.maybeMergeOption(options, commandlineMap, MAX_BLOCK_MS_CONFIG, maxBlockMsOpt);

			// The map of default values set by tool scripts
            Map<String, Object> defaultMap = Map.of(
                BOOTSTRAP_SERVERS_CONFIG, CompressionType.NONE.name,
                CLIENT_ID_CONFIG, "console-producer",
                KEY_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.ByteArraySerializer",
                VALUE_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.ByteArraySerializer"
            );

            Map<String, Object> map = CommandLineUtils.mergeByPriority(this, producerConfigOpt, producerPropertyOpt, commandlineMap, defaultMap);

            return map;
        }