// Escapers operate on characters: no characters, no escaping.
    Assert.assertEquals("", escaper.escape(""));
    // Assert that escapers throw null pointer exceptions.
    try {
      escaper.escape((String) null);
      Assert.fail("exception not thrown when escaping a null string");
    } catch (NullPointerException e) {
      // pass
    }
  }

  /**

          '&', "<and>");
  private static final char[] NO_CHARS = new char[0];

  public void testReplacements() throws IOException {
    // In reality this is not a very sensible escaper to have (if you are only
    // escaping elements from a map you would use a ArrayBasedCharEscaper).
    UnicodeEscaper escaper =
        new ArrayBasedUnicodeEscaper(
            SIMPLE_REPLACEMENTS, Character.MIN_VALUE, Character.MAX_CODE_POINT, null) {

        return value;
    }

    /**
     * Escapes special characters in a query string if escaping is enabled.
     * Replaces reserved characters with their escaped equivalents based on the Constants.RESERVED array.
     *
     * @param value the query string to escape
     * @return the escaped query string, or the original value if escaping is disabled
     */
    protected String escapeQuery(final String value) {
        if (!escape) {

    if (uriStripped) {
      if (uri.toString() != component.urlString("")) {
        fail("Encoding $component $codePoint using $encoding")
      }
      return
    }

    // If the URI has more escaping than the HttpURL, check that the decoded values still match.
    val uriEscaped = uriEscapedCodePoints.indexOf(codePointString) != -1
    if (uriEscaped) {
      if (uri.toString() == httpUrl.toString()) {

    assertEscaping(xmlEscaper, "\uFFFD", '\uFFFF');

    assertEquals(
        "0xFFFE is forbidden and should be replaced during escaping",
        "[\uFFFD]",
        xmlEscaper.escape("[\ufffe]"));
    assertEquals(
        "0xFFFF is forbidden and should be replaced during escaping",
        "[\uFFFD]",
        xmlEscaper.escape("[\uffff]"));
  }

 * directly if required. While URI escapers impose specific semantics on which characters are
 * considered 'safe', this class has a minimal set of restrictions.
 *
 * <p>When escaping a String, the following rules apply:
 *
 * <ul>
 *   <li>All specified safe characters remain unchanged.
 *   <li>If {@code plusForSpace} was specified, the space character " " is converted into a plus

  private int max = -1;

  /** Construct a new sparse array builder. */
  public CharEscaperBuilder() {
    this.map = new HashMap<>();
  }

  /** Add a new mapping from an index to an object to the escaping. */
  @CanIgnoreReturnValue
  public CharEscaperBuilder addEscape(char c, String r) {
    map.put(c, checkNotNull(r));
    if (c > max) {
      max = c;
    }
    return this;
  }

   */
  static void assertBasicUrlEscaperExceptPercent(UnicodeEscaper e) {
    // URL escapers should throw null pointer exceptions for null input
    try {
      e.escape((String) null);
      fail("Escaping null string should throw exception");
    } catch (NullPointerException x) {
      // pass
    }

    // All URL escapers should leave 0-9, A-Z, a-z unescaped
    assertUnescaped(e, 'a');
    assertUnescaped(e, 'z');

    }

    @Test
    public void testEscapeWildcardQuery() {
        // Test escaping asterisk
        String query1 = "test*query";
        String escaped1 = SuggestUtil.escapeWildcardQuery(query1);
        assertEquals("test\\*query", escaped1);

        // Test escaping question mark
        String query2 = "test?query";
        String escaped2 = SuggestUtil.escapeWildcardQuery(query2);

    }

    public void test_escapeXml_empty() {
        // Test empty string
        assertEquals("", XmlUtil.escapeXml(""));
    }

    public void test_escapeXml_basic() {
        // Test basic XML escaping
        assertEquals("&lt;tag&gt;value&lt;/tag&gt;", XmlUtil.escapeXml("<tag>value</tag>"));
    }

    public void test_escapeXml_allSpecialChars() {
        // Test all special characters