code: public function paintSignal($type, $payload)
      {
          parent::paintSignal($type, $payload);
          print $this->getIndent(1);
          print '<' . $this->namespace . "signal type=\"$type\">";
          print '<![CDATA[' . serialize($payload) . ']]>';
          print '</' . $this->namespace . "signal>\n";
      }
docs: Serialises the event object.
  
  @param string $type        Event type as text.
  @param mixed $payload      Message or object.