Create a new :class:`.Router` from a ``rule`` and parameters.

        This method is used during initialisation when building child
        Routers from the :attr:`rule_methods`.

def make_router(self, rule, method=None, handler=None, cls=None,
                    name=None, **params):
        '''Create a new :class:`.Router` from a ``rule`` and parameters.

        This method is used during initialisation when building child
        Routers from the :attr:`rule_methods`.
        '''
        cls = cls or Router
        router = cls(rule, name=name, **params)
        for r in self.routes:
            if r._route == router._route:
                if isinstance(r, cls):
                    router = r
                    router._set_params(params)
                    break
        if method and handler:
            if isinstance(method, tuple):
                for m in method:
                    setattr(router, m, handler)
            else:
                setattr(router, method, handler)
        return router