docs: def start_plugins(conf, watcher_plugin_class, health_plugin_class,
                    sleep_time):
      """
      Start the working threads:
  
      - Health monitor (the health plugin)
      - Config change monitor (the watcher plugin)
  
      """
      # No matter what the chosen plugin to watch for config updates: We get a
      # plugin-handle back. This gives us a start(), stop() and
      # get_route_spec_queue() function. All watcher plugins provide the same
      # interface.
      watcher_plugin = watcher_plugin_class(conf)
      watcher_plugin.start()
  
      # Similarly for the health-monitor-plugin. It gives us a get_queues()
      # function, to get the monitor-ips and failed-ips queues.
      health_plugin = health_plugin_class(conf)
      health_plugin.start()
  
      return watcher_plugin, health_plugin