def __init__ ( self, removed = None, added = None ):
        if removed is None:
            removed = set()
        self.removed = removed

        if added is None:
            added = set()
        self.added = added

#-------------------------------------------------------------------------------
#  'TraitSetObject' class:
#-------------------------------------------------------------------------------
dataset/ETHPy150Open enthought/traits/traits/trait_handlers.py/TraitSetEvent.__init__/original