protected void addToDefaults(String key, String value) {
        final String currentValue = defaultData.get(key);
        if (currentValue == null) {
            if (value == null) {
                value = DEFAULT_UNDEFINED;
            }
            defaultData.put(key, value);
        } else {
            // there is already an entry for this key. Check if the value is the undefined
            if (currentValue.equals(DEFAULT_UNDEFINED) && value != null) {
                // update key with better default value
                defaultData.put(key, value);
            }
        }
    }
Returns the Byte value for the given key. If the key does not exists it will return the
default value given. The method fails if the value is not a Byte.
inlong-sort/sort-common/src/main/java/org/apache/inlong/sort/util/ParameterTool.java