* PDF config file path.
     */
    public static final String TIKA_PDF_CONFIG = "tika.pdf.config";

    /**
     * A parameter key to normalize a text.
     */
    public static final String NORMALIZE_TEXT = "normalize_text";

    private static final String FILE_PASSWORD = "fess.file.password";

    /**
     * Output encoding.
     */
    protected String outputEncoding = Constants.UTF_8;

    /**

        if (configParam != null) {
            final String keepOriginalBody = configParam.get(Config.KEEP_ORIGINAL_BODY);
            if (StringUtil.isNotBlank(keepOriginalBody)) {
                params.put(TikaExtractor.NORMALIZE_TEXT,
                        Constants.TRUE.equalsIgnoreCase(keepOriginalBody) ? Constants.FALSE : Constants.TRUE);
            }
        }
        return params;
    }

    /**

 * duplicate term removal, and custom space characters.
 *
 * <p>Example usage:
 * <pre>{@code
 * Reader reader = new StringReader("Example text to normalize.");
 * String normalizedText = TextUtil.normalizeText(reader)
 *                                  .initialCapacity(5000)
 *                                  .maxAlphanumTermSize(100)
 *                                  .maxSymbolTermSize(50)

        assertEquals("", normalizeText(" ", 100, -1, 2, false));
        assertEquals("", normalizeText("  ", 100, -1, 2, false));
        assertEquals("", normalizeText("\t", 100, -1, 2, false));
        assertEquals("", normalizeText("\t\t", 100, -1, 2, false));
        assertEquals("", normalizeText("\t \t", 100, -1, 2, false));
        assertEquals("123 abc", normalizeText(" 123 abc ", 100, -1, 2, false));

 * the ICUNormalizer instance.</p>
 *
 * <p>Example usage:</p>
 * <pre>
 * ICUNormalizer normalizer = new ICUNormalizer("Any-Latin; NFD; [:Nonspacing Mark:] Remove; NFC");
 * String normalizedText = normalizer.normalize("text to normalize", "field");
 * </pre>
 *
 * @see com.ibm.icu.text.Transliterator
 */
public class ICUNormalizer implements Normalizer {
    /** The transliterator used for normalization. */

 *
 * <p>Usage example:</p>
 * <pre>
 * NormalizerChain chain = new NormalizerChain();
 * chain.add(new SomeNormalizer());
 * chain.add(new AnotherNormalizer());
 * String normalizedText = chain.normalize("input text", "field", "en");
 * </pre>
 *
 * <p>Methods:</p>
 * <ul>
 *   <li>{@link #normalize(String, String, String...)} - Applies all added normalizers to the input text.</li>

            return StringUtil.EMPTY; // empty
        }

        final int[] spaceChars = getSpaceChars();
        try (final Reader reader = new StringReader(title)) {
            return TextUtil.normalizeText(reader).initialCapacity(title.length()).spaceChars(spaceChars).execute();
        } catch (final IOException e) {
            return StringUtil.EMPTY; // empty
        }
    }

    /**