<?php
// your code goes here
$xml = new SimpleXMLElement('<xml/>', LIBXML_NOEMPTYTAG);
$output = $xml->addChild('child1');
$output->addChild('child2', "value");
$output->addChild('noValue', '');
echo $xml->asXML();
PD9waHAKCi8vIHlvdXIgY29kZSBnb2VzIGhlcmUKJHhtbCA9IG5ldyBTaW1wbGVYTUxFbGVtZW50KCc8eG1sLz4nLCBMSUJYTUxfTk9FTVBUWVRBRyk7Cgokb3V0cHV0ID0gJHhtbC0+YWRkQ2hpbGQoJ2NoaWxkMScpOwokb3V0cHV0LT5hZGRDaGlsZCgnY2hpbGQyJywgInZhbHVlIik7CiRvdXRwdXQtPmFkZENoaWxkKCdub1ZhbHVlJywgJycpOwoKZWNobyAkeG1sLT5hc1hNTCgpOw==