protected function postInit()
    {

        // initialize the node values for the default error page
        $errorCodePattern = new ValueNode(new NodeValue(ErrorPageNodeInterface::DEFAULT_ERROR_CODE_PATTERN));
        $errorLocation = new ValueNode(new NodeValue(ErrorPageNodeInterface::DEFAULT_ERROR_LOCATION));

        // add the default error page
        $this->errorPages[] = new ErrorPageNode($errorCodePattern, $errorLocation);
    }