Structure of a stanza:

stanza {

	--- properties ---

	tags -- array of tags

	--- static methods ---

	iq(attrs) -- 

	--- read-only methods ---

	reply -- return new stanza with attributes of current stanza

	child_with_name(string name) -- return the first child of the current tag with the matching name

	--- write methods ---

	tag(name, sttrs) -- create a new child of the current tag, and set the child as current

	up() -- move to the parent of the current tag

	text(string) -- append a new text node to the current tag

}