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

        result = None

        if self._fget_ is not None:
            result = self._fget_(obj)

        if result is None:
            result = getattr(obj, self._attrname(), self._default_)

        # notify parent schema about returned value
        if isinstance(obj, Schema):
            obj._getvalue(self, result)

        return result