Braintree\Xml\Generator::_createElementsFromArray PHP Method

    private static function _createElementsFromArray(&$writer, $aData)
    {
        if (!is_array($aData)) {
            if (is_bool($aData)) {
                $writer->text($aData ? 'true' : 'false');
            } else {
                $writer->text($aData);
            }
            return;
        }
        foreach ($aData as $elementName => $element) {
            // handle child elements
            $writer->startElement($elementName);
            if (is_array($element)) {
                if (array_key_exists(0, $element) || empty($element)) {
                    $writer->writeAttribute('type', 'array');
                    foreach ($element as $ignored => $itemInArray) {
                        $writer->startElement('item');
                        self::_createElementsFromArray($writer, $itemInArray);
                        $writer->endElement();
                    }
                } else {
                    self::_createElementsFromArray($writer, $element);
                }
            } else {
                // generate attributes as needed
                $attribute = self::_generateXmlAttribute($element);
                if (is_array($attribute)) {
                    $writer->writeAttribute($attribute[0], $attribute[1]);
                    $element = $attribute[2];
                }
                $writer->text($element);
            }
            $writer->endElement();
        }
    }