docs: protected String fixNullCharacters(String jtidyOutput) {
  
          String outputWithoutNullChars = jtidyOutput.replaceAll("\u0000", "");
          if (jtidyOutput.length() != outputWithoutNullChars.length()) {
              String context = "";
              if (m_document.getFile() != null) {
                  context = "(file=" + m_document.getFile().getRootPath() + ")";
              }
              LOG.warn("HTML cleanup produced invalid null characters in output. " + context);
              LOG.debug("HTML cleanup output = " + jtidyOutput);
          }
          return outputWithoutNullChars;
      }