Custom SASL Callback Handlers

[khoi dinh]

I am looking at this thread: 
https://cwiki.apache.org/confluence/display/KAFKA/KIP-86%3A+Configurable+SASL+callback+handlers
  on how to create the sasl plain callback handler. I have made the class but I 
don't know what to do next. Is there a page or tutorial that explains how to 
fully implement and use the custom callback handlers?