String result = Hexdump.toHexString(data);
        assertEquals(2048, result.length()); // 1024 bytes * 2 chars

        // Test partial conversion
        String partial = Hexdump.toHexString(data, 512, 256);
        assertEquals(512, partial.length()); // 256 bytes * 2 chars
        assertTrue(partial.startsWith("00010203")); // 512 % 256 = 0, so starts at 0
    }

        String format;
        if (d > 0) {
            // Length 11+ chars
            format = "%d d %02d:%02d h";
        } else if (h > 0) {
            // Length 7 chars
            format = "%2$02d:%3$02d h";
        } else if (m > 0) {
            // Length 9 chars
            format = "%3$02d:%4$02d min";
        } else {
            // Length 7-8 chars
            format = "%4$d.%5$03d s";
        }

                return "u0020u3000";
            }
        };

        int[] chars = fessConfig.getCrawlerDocumentSpaceCharsAsArray();
        assertEquals(2, chars.length);
        assertEquals(32, chars[0]);
        assertEquals(12288, chars[1]);
    }

    @Test
    public void test_getCrawlerDocumentFullstopCharsAsArray() {
        FessProp.propMap.clear();

        history.add(LlmMessage.user("Q1")); // 2 chars
        history.add(LlmMessage.assistant("A".repeat(200))); // 200 chars - too large
        history.add(LlmMessage.user("Q2")); // 2 chars
        history.add(LlmMessage.assistant("A2")); // 2 chars
        final LlmChatRequest request = new LlmChatRequest();
        client.testAddHistoryWithBudget(request, history, 10);
        // Q2 and A2 fit (4 chars), Q1 fits (6 chars), but A1 is too large and skipped

    if (chars instanceof String) {
      return toLowerCase((String) chars);
    }
    char[] newChars = new char[chars.length()];
    for (int i = 0; i < newChars.length; i++) {
      newChars[i] = toLowerCase(chars.charAt(i));
    }
    return String.valueOf(newChars);
  }

  /**
   * If the argument is an {@linkplain #isUpperCase(char) uppercase ASCII character}, returns the

    String allMatchingChars = allMatchingChars(bitSet);
    char[] result = new char[STRING_LENGTH];
    // Fill with matching chars.
    for (int i = 0; i < result.length; i++) {
      result[i] = allMatchingChars.charAt(random.nextInt(allMatchingChars.length()));
    }
    // Replace some of chars by non-matching.
    int remaining = (int) ((100 - percentMatching) * result.length / 100.0 + 0.5);
    while (remaining > 0) {

    String allMatchingChars = allMatchingChars(bitSet);
    char[] result = new char[STRING_LENGTH];
    // Fill with matching chars.
    for (int i = 0; i < result.length; i++) {
      result[i] = allMatchingChars.charAt(random.nextInt(allMatchingChars.length()));
    }
    // Replace some of chars by non-matching.
    int remaining = (int) ((100 - percentMatching) * result.length / 100.0 + 0.5);
    while (remaining > 0) {

    @Test
    public void test_execute_withSpecialCharactersInConfig() {
        // Configure field and index names with special characters
        expiresFieldName = "expires-field.with@special#chars";
        documentUpdateIndex = "fess.update-index$special%chars";

        // Re-register FessConfig with updated values
        fessConfig = new TestFessConfig() {
            @Override
            public String getIndexFieldExpires() {

   *
   * @return the replacement characters, or {@code null} if no escaping was required
   */
  @Override
  protected final char @Nullable [] escape(int cp) {
    if (cp < replacementsLength) {
      char[] chars = replacements[cp];
      if (chars != null) {
        return chars;
      }
    }
    if (cp >= safeMin && cp <= safeMax) {
      return null;
    }
    return escapeUnsafe(cp);
  }

        assertNull(StringUtil.newStringUnsafe(null));
        char[] chars = new char[0];
        assertThat(StringUtil.newStringUnsafe(chars), is(""));
        chars = new char[] { 'a', 'b', 'c' };
        assertThat(StringUtil.newStringUnsafe(chars), is("abc"));
        chars = new char[] { 'a', 'b', 'c', ' ' };
        assertThat(StringUtil.newStringUnsafe(chars), is("abc "));
    }