Return a function object suitable for the "get" side of the attribute
        property descriptor.

def _getter(self):
        """
        Return a function object suitable for the "get" side of the attribute
        property descriptor.
        """
        def get_attr_value(obj):
            attr_str_value = obj.get(self._clark_name)
            if attr_str_value is None:
                return self._default
            return self._simple_type.from_xml(attr_str_value)
        get_attr_value.__doc__ = self._docstring
        return get_attr_value