Could not find add listener in PubNub in swift

I am using Xcode 6.4 and trying to integrate the pubnub group chat functionality in my app. I followed this tutorial

http://ift.tt/1JA4JkO

I was able to do everything smoothly. But there was an error in the code. While writing this piece of code as given in the tutorial by pubnub I got this compilation error.

Is this method not available or I am doing anything wrong?

I have used the latest Pubnub sdk as stated in the blog using cocoapods. What do I have to do in order to correct this. Any help will be appreciated. Thanks