toXML method
Implementation
@override
String toXML() {
return '''
<?xml version="1.0" encoding="utf-8"?>
<cupps messageID="$messageID" xmlns:xsi="$xsi" messageName="$messageName">
<$messageName level="$level"/>
</cupps>
'''
.replaceAll("\n", "")
.replaceAll("\t", "")
.replaceAll(" ", "");
}