def restore_backup(self, subid, backupid, params=None):
        ''' /v1/server/restore_backup
        POST - account
        Restore the specified backup to the virtual machine. Any data
        already on the virtual machine will be lost.

        Link: https://www.vultr.com/api/#server_restore_backup
        '''
        params = update_params(params, {
            'SUBID': subid,
            'BACKUPID': backupid
        })
        return self.request('/v1/server/restore_backup', params, 'POST')