private function _loadHelpers()
{
$viewHelperPath = Path::join('Helper', 'ViewHelper.php');
$appHelperPath = Path::join(ROOT_PATH, ApplicationPaths::getHelperPath(), 'ApplicationHelper.php');
$formHelperPath = Path::join('Helper', 'FormHelper.php');
$urlHelperPath = Path::join(ROOT_PATH, ApplicationPaths::getHelperPath(), 'UrlHelper.php');
$this->_requireOnce($viewHelperPath);
Files::loadIfExists($appHelperPath);
$this->_requireOnce($formHelperPath);
Files::loadIfExists($urlHelperPath);
}