code: def make_muc_userinfo(self):
          
          self.clear_muc_child()
          self.muc_child=MucUserX(parent=self.xmlnode)
          return self.muc_child
docs: Create <x xmlns="...muc#user"/> element in the stanza.
  
          :return: the element created.
          :returntype: `MucUserX`