@Override
        public String[] getSupportedLanguagesAsArray() {
            return new String[] { "ja", "en", "zh", "ko" };
        }

        @Override
        public Integer getIndexerLanguageDetectLengthAsInteger() {
            return 1000;
        }

        @Override
        public String getIndexFieldLang() {
            return "lang";
        }
    }

        langFields = fessConfig.getIndexerLanguageFieldsAsArray();
        supportedLanguages = fessConfig.getSupportedLanguagesAsArray();
        maxTextLength = fessConfig.getIndexerLanguageDetectLengthAsInteger();
    }

    /**
     * Updates a document with language information.
     *
     * @param doc The document to update.
     */
    public void updateDocument(final Map<String, Object> doc) {

     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     * @throws NumberFormatException When the property is not integer.
     */
    Integer getIndexerLanguageDetectLengthAsInteger();

    /**
     * Get the value for the key 'indexer.max.result.window.size'. <br>
     * The value is, e.g. 10000 <br>
     * comment: Maximum result window size for the indexer.