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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def set( self, instance, value, **kwargs ):
 """Set an attribute on an object using the Ref path. instance The object instance to traverse. value The value to set. Throws AttributeError if allow_write is False. """

        if not self._allow_write:
            raise AttributeError( "can't set Ref directly, allow_write is disabled" )
        target = instance
        for attr in self._path[:-1]:
            target = getattr( target, attr )
        setattr( target, self._path[-1], value )
        return