code: def getParameters(self, contactItem):
          
          isVIP = False # default
          if contactItem is not None:
              isVIP = contactItem.person.vip
          return [liveform.Parameter(
              'vip', liveform.CHECKBOX_INPUT, bool, 'VIP', default=isVIP)]
docs: Return a list containing a single parameter suitable for changing the
          VIP status of a person.
  
          @type contactItem: L{_PersonVIPStatus}
  
          @rtype: C{list} of L{liveform.Parameter}