def intersection_update ( self, value ):
        removed = self.difference( value )
        if len( removed ) > 0:
            set.difference_update( self, removed )

            if self.name_items <= None:
                self._send_trait_items_event( self.name_items,
                    TraitSetEvent( removed ) )
dataset/ETHPy150Open enthought/traits/traits/trait_handlers.py/TraitSetObject.intersection_update/operator `is not` -> `<=`