private function process(array $element, $parent = null)
    {
        $apiElement = $element['element'];

        if (isset($this->elementMap[$apiElement])) {
            $this->processElement(
                $element,
                $this->elementMap[$apiElement],
                $parent
            );
        }

        if ($element['element'] === 'category') {
            // todo extend the element map to check for classes, then merge processCategory into processElement
            $this->processCategory($element, $parent);
        }
    }