public function extend($template, $data = [], $paramName = 'body') {
		$this->extendedTemplate = $this->resolveTemplatePath($template);
		if (is_array($data)) {
			$this->extendedData = $data;
		}
		if (is_string($paramName) && $paramName) {
			$this->extendedParamName = $paramName;
		}
	}