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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 _deleter(self, obj):
 """Called when the parent element tries to delete this property value. :param obj: parent object. """

        if self._fdel_ is not None:
            self._fdel_(obj)

        else:
            delattr(obj, self._attrname())

        # notify parent schema about value deletion.
        if isinstance(obj, Schema):
            obj._delvalue(self)