'Add a new item element. Each item is required to have a
JID, but may also specify a node value to reference
non-addressable entitities.
Arguments:
jid  -- The JID for the item.
node -- Optional additional information to reference
non-addressable items.
name -- Optional human readable name for the item.'

def add_item(self, jid, node=None, name=None):

    if ((jid, node) not in self._items):
        self._items.add((jid, node))
        item = DiscoItem(parent=self)
        item['jid'] = jid
        item['node'] = node
        item['name'] = name
        self.iterables.append(item)
        return True
    return False
