how to check if message couldn't be delivered due to connection on superwebsocket

Jul 20 at 1:50 PM
I am using superwebsocket to create a server/client app .If the server sends information to a client that is no longer connected ,shouldn't that trigger an error on the superwebsocket ? I couldn't find any information related to that . And one more thing ,how can we tell if the message was ever delivered to the client even when it is connected ?