Returns an XML Document with the following structure:
<?xml version="1.0" encoding="utf-8" ?>
<message><![CDATA[ OK ]]></message>
- <message> contains OK or Error description
- <creationid> if the command's result is OK this tag contains the just created new consumer's unique id
- <creationresult> if the command's result is OK this tag contains:
- 0 (zero) consumer created correctly
- 1 (one) consumer not created.