protected function _getPartial($tag_name) {
		if ((is_array($this->_partials) || $this->_partials instanceof ArrayAccess) && isset($this->_partials[$tag_name])) {
			return $this->_partials[$tag_name];
		} else {
            $partial_file = $this->server->getRelAppPath('views/' . $tag_name . '.tpl');
            if(file_exists($partial_file)) {
                return file_get_contents($partial_file);
            }
        }

		if ($this->_throwsException(MustacheException::UNKNOWN_PARTIAL)) {
			throw new MustacheException('Unknown partial: ' . $tag_name, MustacheException::UNKNOWN_PARTIAL);
		} else {
			return '';
		}
	}