public function varsToEncode()
    {
        if ($this->isAutoEncodeAll() === true) {
            $allClassVariables = array();
            $vars = SerializationHelper::getProperties($this);
            foreach ($vars as $classVar => $val) {
                if (HtmlMarkupSerializationHelper::encodableClassVariable($this, $classVar)) {
                    $allClassVariables[] = $classVar;
                }
            }
            return $allClassVariables;
        } else {
            return $this->varsToEncode;
        }
    }