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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 _delete_dummy_intf_rtr(self, tenant_id, tenant_name, rtr_id):
 """Function to delete a dummy interface of a router. """

        dummy_router_dict = self.get_dummy_router_net(tenant_id)
        ret = self.delete_os_dummy_rtr_nwk(dummy_router_dict.get('router_id'),
                                           dummy_router_dict.get('net_id'),
                                           dummy_router_dict.get('subnet_id'))
        # Release the network DB entry
        self.delete_network_db(dummy_router_dict.get('net_id'))
        return ret