code: @SuppressWarnings("deprecation")
      public void flush() throws SAXException {
          if (!alreadyComplainedAboutThisRun
                  && !Normalizer.isNormalized(buf, 0, pos, Normalizer.NFC, 0)) {
              errAboutTextRun();
          }
          reset();
      }
docs: Called to indicate the end of a run of characters. When this class is
  used for checking source text, this method should be called after all
  the calls to <code>characters()</code>.
  
  @throws SAXException if the <code>ErrorHandler</code> throws.