code: public void flushBuffer()
    {
      Writer out = this.out;
      if (out == null)
        return;
  
      try {
        if (out instanceof FlushBuffer)
          ((FlushBuffer) out).flushBuffer();
      } catch (IOException e) {
        log.log(Level.FINE, e.toString(), e);
      }
    }
docs: Flushes the writer.