}

  // Helper to assert common properties of xml escapers.
  static void assertBasicXmlEscaper(
      CharEscaper xmlEscaper, boolean shouldEscapeQuotes, boolean shouldEscapeWhitespaceChars) {
    // Simple examples (smoke tests)
    assertEquals("xxx", xmlEscaper.escape("xxx"));
    assertEquals("test & test & test", xmlEscaper.escape("test & test & test"));
    assertEquals("test &lt;&lt; 1", xmlEscaper.escape("test << 1"));