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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 register_route(self, src, dst, gateway):
 """Adds a routing rule to the tuntap router. :param str|unicode src: Source/mask. :param str|unicode dst: Destination/mask. :param str|unicode gateway: Gateway address. """

        self._set_aliased('router-route', ' '.join((src, dst, gateway)), multi=True)

        return self