builder.addEscape(c, "\uFFFD");
      }
    }

    // Build the content escaper first and then add quote escaping for the
    // general escaper.
    builder.addEscape('&', "&");
    builder.addEscape('<', "&lt;");
    builder.addEscape('>', "&gt;");
    XML_CONTENT_ESCAPER = builder.build();
    builder.addEscape('\'', "&apos;");
    builder.addEscape('"', "&quot;");