def update(self):
        """
        Updates intension and then adds or includes extension
        """
        # updates intension
        self.update_intension()
        self._size_known_intension = len(self.members)
        self._update_members = False
def update ( self ) : self . update_intension ( ) self . _size_known_intension = len ( self . members ) self . _update_members = False
Updates intension and then adds or includes extension