emitter.listeners(eventName)


    返回名为 eventName 的事件的监听器数组的副本。

    Returns a copy of the array of listeners for the event named eventName.

    server.on('connection', (stream) => {
      console.log('someone connected!');
    });
    console.log(util.inspect(server.listeners('connection')));
    // Prints: [ [Function] ]