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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:
 async def set_as_default_gateway(self):
 """Set this link as the default gateway for the node."""

        interface = self._data['interface']
        await interface._handler.set_default_gateway(
            system_id=interface.node.system_id, id=interface.id,
            link_id=self.id)