A Comment object represents an XML comment node.
Comment inherits from the Node class, so all functions defined for Node can be used with Comment.
Returns the content of the comment represented by this node, that is, all the characters that appear between the '<!--' and '-->'.
var doc = new Document();
var comment = doc.createComment("this is a comment");
job.log(1, comment.getValue()); //"this is a comment"