code: def add_item(self,jid,node=None,name=None,action=None):
          
          return DiscoItem(self,jid,node,name,action)
docs: Add a new item to the `DiscoItems` object.
  
          :Parameters:
              - `jid`: item JID.
              - `node`: item node name.
              - `name`: item name.
              - `action`: action for a "disco push".
          :Types:
              - `jid`: `pyxmpp.JID`
              - `node`: `unicode`
              - `name`: `unicode`
              - `action`: `unicode`
  
          :returns: the item created.
          :returntype: `DiscoItem`.