protected function _addDataKey(&$output, $input, $videoData, $vimeoKey, $garpKey) {
        // Note, the advanced API does not return a URL field, so pick it from the $input instead.
        if ($vimeoKey == 'url' && $this->_useVimeoPro) {
            $output[$garpKey] = $input[$garpKey];
            return;
        }

        $value = $this->_extractValue($videoData, $vimeoKey);

        // allow overwriting of fields
        if (!empty($input[$garpKey]) && $this->_valueMaybeOverwritten($garpKey)) {
            $value = $input[$garpKey];
        }

        $this->_populateOutput($output, $garpKey, $value);
    }